Letters to the Editor


NaMYB8 regulates distinct, optimally distributed herbivore defense traits  
Author: Martin Schäfer, Christoph Brütting, Shuqing Xu, Zhihao Ling, Anke Steppuhn, Ian T. Baldwin and Meredith C. Schuman
DOI: 10.1111/jipb.12593
      
    

When herbivores attack, plants specifically reconfigure their metabolism. Herbivory on the wild tobacco Nicotiana attenuata strongly induces the R2/R3 MYB transcriptional activator MYB8, which was reported to specifically regulate the accumulation of phenolamides (PAs). We discovered that transcriptional regulation of trypsin protease inhibitors (TPIs) and a threonine deaminase (TD) also depend on MYB8 expression. Induced distributions of PAs, TD and TPIs all meet predictions of optimal defense theory: their leaf concentrations increase with the fitness value and the probability of attack of the tissue. Therefore, we suggest that these defensive compounds have evolved to be co-regulated by MYB8.

Abstract (Browse 49)  |  References  |  Full Text HTML  |  Full Text PDF  |  Cited By       
Fitness consequences of a clock pollinator filter in Nicotiana attenuata flowers in nature  
Author: Felipe Yon, Danny Kessler, Youngsung Joo, Sang-Gyu Kim and Ian T. Baldwin1
DOI: 10.1111/jipb.12579
      
    

Nicotiana attenuata flowers, diurnally open, emit scents and move vertically to interact with nocturnal hawkmoth and day-active hummingbird pollinators. To examine the fitness consequences of these floral rhythms, we conducted pollination trials in the plant's native habitat with phase-shifted flowers of plants silenced in circadian clock genes. The results revealed that some pollination benefits observed under glasshouse conditions were not reproduced under natural field conditions. Floral arrhythmicity increased pollination success by hummingbirds, while reducing those by hawkmoths in the field. Thus floral circadian rhythms may influence a plant's fitness by filtering pollinators leading to altered seed set from outcrossed pollen.

Abstract (Browse 53)  |  References  |  Full Text HTML  |  Full Text PDF  |  Cited By       
The signals to trigger the initiation of ovule enlargement are from the pollen tubes: The direct evidence  
Author: Sheng Zhong, Jun Zhang and Li-Jia Qu
Journal of Integrative Plant Biology 2017 59(9): 600每603
Published Online: August 16, 2017
DOI: 10.1111/jipb.12577
      
    

In angiosperms, initiation of ovule enlargement represents the start of seed development, the molecular mechanism of which is not yet elucidated. It was previously reported that pollen tube contents, rather than double fertilization, can trigger ovule enlargement. However, it remains unclear whether the signal(s) to trigger the initiation of ovule enlargement are from the sperm cells or from the pollen tubes. Recently, we identified a mutant drop1− drop2−, which produces pollen tubes with no sperm cells. Taking advantage of this special genetic material, we conducted pollination assays, and found that the ovules pollinated with drop1− drop2− pollen could initiate the enlargement and exhibited significant enlarged sizes at 36 h after pollination in comparison with those unpollinated ovules. However, the sizes of the ovules pollinated with drop1− drop2− pollen are significantly smaller than those of the ovules pollinated with wild-type pollen. These results demonstrate that the pollen tube, rather than the sperm cells, release the signal to trigger the initiation of ovule enlargement, and that double fertilization is required for further enlargement of the seeds.

Abstract (Browse 43)  |  References  |  Full Text HTML  |  Full Text PDF  |  Cited By       
Seed size is an important trait of higher plants, especially of crops that are food resources for humans. Ovule enlargement is the start of seed size expansion. We find that the signal to trigger ovule enlargement comes from the pollen tube, not from the sperm cells, or from fertilization.
Seed dispersal by hornets: An unusual insect-plant mutualism  
Author: Gao Chen, Zheng-Wei Wang, Yan Qin and Wei-Bang Sun
DOI: 10.1111/jipb.12568
      
    

Vespicochory, seed dispersal by hornets, is a rare seed dispersal mechanism in angiosperms and, to date, there are few records of this phenomenon. Through field investigations and behavioral assays conducted in four populations of Stemona tuberosa from 2011–2016, we demonstrate that hornets are the primary seed dispersers of S. tuberosa and play an important role in “long-distance” seed dispersal in this species. Furthermore, some ant species act as secondary dispersers and may transport the seeds to safe sites. Hornets and ants provide complementary seed dispersal at different spatial scales. This unique example of insect-plant mutualism may be an underestimated but important strategy to ensure “long-distance” seed dispersal in other myrmecochorous plants.

Abstract (Browse 86)  |  References  |  Full Text HTML  |  Full Text PDF  |  Cited By       
THESEUS1 positively modulates plant defense responses against Botrytis cinerea through GUANINE EXCHANGE FACTOR4 signaling  
Author: Shaofeng Qu, Xi Zhang, Yutong Song, Jinxing Lin and Xiaoyi Shan
DOI: 10.1111/jipb.12565
      
    

The plant cell wall is an important interface for sensing pathogen attack and activating signaling pathways that promote plant immune responses. THESEUS1 (THE1) acts as a sensor of cell wall integrity that controls cell elongation during plant growth. However, no specific role for THE1 in plant defense responses has been reported. Here, we found that THE1 interacts with GUANINE EXCHANGE FACTOR4 (GEF4) and that both proteins play regulatory roles in plant resistance to the necrotrophic fungus Botrytis cinerea. Genetic analysis showed that THE1 and GEF4 function in the same genetic pathway to mediate plant defense responses. In addition, using transcriptome analysis, we identified various genes (such as defense-related, secondary metabolite-related, and transcription factor genes) that are likely downstream targets in the THE1-GEF4 signaling pathway. Our results suggest that THE1 functions as an upstream regulator of GEF4 signaling to positively regulate defense responses against B. cinerea in Arabidopsis.

Abstract (Browse 118)  |  References  |  Full Text HTML  |  Full Text PDF  |  Cited By       
Arabidopsis TOR signaling is essential for sugar-regulated callus formation  
Author: Kyounghee Lee and Pil Joon Seo
Journal of Integrative Plant Biology 2017 59(10): 742每746
Published Online: June 17, 2017
DOI: 10.1111/jipb.12560
      
    

Dedifferentiation is a remarkable process that produces pluripotent stem cells from differentiated somatic cells to ensure developmental plasticity. Plants have evolved the ability of cellular dedifferentiation, and signaling cascades related to auxin and cytokinin-dependent callus formation have been extensively investigated. However, the molecular mechanism underlying sugar-dependent callus formation remains unknown. Here, we show that sugar-dependent callus formation is mainly regulated by the TOR-E2Fa module in Arabidopsis. Sugar-activated TOR kinase phosphorylates and stabilizes E2Fa proteins to transcriptionally activate S-phase genes during callus formation. In parallel, E2Fa is transcriptionally regulated by the ARF-LBD transcription cascade. Multi-layered regulation of E2Fa by sugar and auxin is likely to shape balanced cellular dedifferentiation capability in Arabidopsis.

Abstract (Browse 147)  |  References  |  Full Text HTML  |  Full Text PDF  |  Cited By       
As an early step of cellular dedifferentiation, tissue explants induce pluripotent cell mass callus. Callus formation involves active cell division and requires sugar signaling. This study demonstrates that sugar supply is essential for robust callus formation, and sugar-dependent callus formation is mainly regulated by TOR-E2Fa module in Arabidopsis.
Mutation in a novel gene SMALL AND CORDATE LEAF 1 affects leaf morphology in cucumber  
Author: Dongli Gao, Chunzhi Zhang, Shu Zhang, Bowen Hu, Shenhao Wang, Zhonghua Zhang and Sanwen Huang
Journal of Integrative Plant Biology 2017 59(10): 736每741
Published Online: June 9, 2017
DOI: 10.1111/jipb.12558
      
    

Plant species exhibit substantial variation in leaf morphology. We isolated a recessive mutant gene termed small and cordate leaf 1 (scl1) that causes alteration in both leaf size and shape of cucumber. Compared to wild type leaves, the scl1 mutant had fewer numbers of epidermal pavement cells. A single nucleotide polymorphism was associated with this leaf phenotype, which occurred in a putative nucleoside bisphosphate phosphatase. RNA-seq analysis of the wild type and scl1 mutant leaves suggested that SCL1 regulation may not involve known hormonal pathways. Our work identified a candidate gene for SCL1 that may play a role in leaf development.

Abstract (Browse 148)  |  References  |  Full Text HTML  |  Full Text PDF  |  Cited By       
The size and shape of leaves are important factors influencing the success of plants and agricultural productivity. This work identified a mutant locus small and cordate leaf 1 (scl1) that causes the alteration of leaf size and shape in cucumber.
Arabidopsis adaptor protein 1G is critical for pollen development  
Author: Chong Feng, Jia-Gang Wang, Hai-Hong Liu, Sha Li and Yan Zhang
Journal of Integrative Plant Biology 2017 59(9): 594每599
Published Online: May 24, 2017
DOI: 10.1111/jipb.12556
      
    

Pollen development is a pre-requisite for sexual reproduction of angiosperms, during which various cellular activities are involved. Pollen development accompanies dynamic remodeling of vacuoles through fission and fusion, disruption of which often compromises pollen viability. We previously reported that the Y subunit of adaptor protein 1 (AP1G) mediates synergid degeneration during pollen tube reception. Here, we demonstrate that AP1G is essential for pollen development. AP1G loss-of-function resulted in male gametophytic lethality due to defective pollen development. By ultrastructural analysis and fluorescence labeling, we demonstrate that AP1G loss-of-function compromised dynamic vacuolar remodeling during pollen development and impaired vacuolar acidification of pollen. Results presented here support a key role of vacuoles in gametophytic pollen development.

Abstract (Browse 207)  |  References  |  Full Text HTML  |  Full Text PDF  |  Cited By       
AP1G, adaptor protein 1, is essential for protein sorting at the trans-Golgi network/early endosomes. This study demonstrates that functional loss of the 污 subunit of AP1G resulted in male gametophytic lethality by affecting vacuolar remodeling and acidification during pollen development.
Overexpression of GhFIM2 propels cotton fiber development by enhancing actin bundle formation  
Author: Min Zhang, Li-Bo Han, Wen-Yan Wang, Shen-Jie Wu, Gai-Li Jiao, Lei Su, Gui-Xian Xia and Hai-Yun Wang
Journal of Integrative Plant Biology 2017 59(8): 531每534
Published Online: May 5, 2017
DOI: 10.1111/jipb.12552
      
    

Cell elongation and secondary wall deposition are two consecutive stages during cotton fiber development. The mechanisms controlling the progression of these two developmental phases remain largely unknown. Here, we report the functional characterization of the actin-bundling protein GhFIM2 in cotton fiber. Overexpression of GhFIM2 increased the abundance of actin bundles, which was accompanied with accelerated fiber growth at the fast-elongating stage. Meanwhile, overexpression of GhFIM2 could propel the onset of secondary cell wall biogenesis. These results indicate that the dynamic rearrangement of actin higher structures involving GhFIM2 plays an important role in the development of cotton fiber cells.

Abstract (Browse 260)  |  References  |  Full Text HTML  |  Full Text PDF  |  Cited By       
This study demonstrated that actin bundling protein GhFIM2 is involved in the dynamic remodeling of actin cytoskeleton in developing cotton fiber. Overexpression of GhFIM2 accelerated the fiber cell growth at the fast-elongating stage and led to an early deposition of the secondary cell wall.
Natural hybridization and reproductive isolation between two Primula species  
Author: Yanping Xie, Xingfu Zhu, Yongpeng Ma, Jianli Zhao, Li Li and Qingjun Li
Journal of Integrative Plant Biology 2017 59(8): 526每530
Published Online: April 21, 2017
DOI: 10.1111/jipb.12546
      
    

Natural hybridization frequently occurs in plants and can facilitate gene flow between species, possibly resulting in species refusion. However, various reproductive barriers block the formation of hybrids and maintain species integrity. Here, we conducted a field survey to examine natural hybridization and reproductive isolation (RI) between sympatric populations of Primula secundiflora and P. poissonii using ten nuclear simple sequence repeat (SSR) loci. Although introgressive hybridization occurred, species boundaries between P. secundiflora and P. poissonii were maintained through nearly complete reproductive isolation. These interfertile species provide an excellent model for studying the RI mechanisms and evolutionary forces that maintain species boundaries.

Abstract (Browse 245)  |  References  |  Full Text HTML  |  Full Text PDF  |  Cited By       
Natural hybridization possibly results in species refusion. However, various reproductive barriers block the formation of hybrids and maintain species integrity. Here, we examined natural hybridization and reproductive isolation between sympatric populations of Primula secundiflora and P. poissonii. The results suggest specific boundaries maintained well through nearly complete reproductive isolation.
Arabidopsis Forkhead-Associated Domain Protein 3 negatively regulates peroxisome division  
Author: Mintu Desai, Ronghui Pan and Jianping Hu
Journal of Integrative Plant Biology 2017 59(7): 454每458
Published Online: March 23, 2017
DOI: 10.1111/jipb.12542
      
    

Peroxisomes are ubiquitous and dynamic eukaryotic organelles capable of altering their abundance in response to environmental and developmental cues, yet the regulatory mechanism of plant peroxisome division/proliferation is unclear. To identify transcriptional regulators of the peroxisome division factor gene PEX11b, we performed a nuclear pull-down experiment and identified Arabidopsis Forkhead-Associated Domain Protein 3 (FHA3) as a novel protein that binds to the promoter of PEX11b. Our data supported the conclusion that, in contrast to the previously identified HY5 HOMOLOG (HYH) protein that promotes the transcription of PEX11b, FHA3 is a negative regulator of PEX11b expression and peroxisome division.

Abstract (Browse 1016)  |  References  |  Full Text HTML  |  Full Text PDF  |  Cited By       
Peroxisomes are essential and dynamic organelles capable of changing abundance through division and proliferation in response to environmental and developmental cues. This work identified an Arabidopsis transcription factor Forkhead-Associated Domain Protein 3 (FHA3), which negatively regulates peroxisome division by repressing the expression of the peroxisome division factor gene PEX11b.
BIK1 cooperates with BAK1 to regulate constitutive immunity and cell death in Arabidopsis  
Author: Jun Liu, Sufen Chen, Lijuan Chen, Qi Zhou, Menglong Wang, Dongru Feng, Jian-Feng Li, Jinfa Wang, Hong-Bin Wang and Bing Liu
Journal of Integrative Plant Biology 2017 59(4): 234每239
Published Online: February 22, 2017
DOI: 10.1111/jipb.12529
      
    

In Arabidopsis, both the membrane-anchored receptor-like kinase (RLK) BAK1 and the receptor-like cytoplasmic kinase (RLCK) BIK1 are important mediators of transmembrane signal transduction that regulate plant development and immunity. However, little attention has been paid to their genetic association. This study found the bak1 bik1 double mutant of Arabidopsis displayed a severe dwarfism phenotype due to constitutive immunity and cell death in developing plants. These data suggest that BIK1 cooperates with BAK1 to regulate constitutive immunity and cell death.

Abstract (Browse 300)  |  References  |  Full Text HTML  |  Full Text PDF  |  Cited By       
bak1 bik1 double mutants showed a severe dwarfism phenotype. The constitutive immune activation was mainly responsible for the cell death and developmental defects in bak1 bik1 double mutants. This study indicated that BAK1 and BIK1 are critical for regulation of the constitutive immune response and cell death in Arabidopsis.
Tonoplast targeting of VHA-a3 relies on a Rab5-mediated but Rab7-independent vacuolar trafficking route  
Author: Qiang-Nan Feng, Yan Zhang and Sha Li
Journal of Integrative Plant Biology 2017 59(4): 230每233
Published Online: February 15, 2017
DOI: 10.1111/jipb.12526
      
    

Vacuolar trafficking routes and their regulators have recently drawn lots of attention in plant cell biology. A recent study reported the discovery of a plant-specific vacuolar trafficking route, i.e., a direct ER-to-vacuole route, through analysis of VHA-a3 subcellular targeting, a key component for the tonoplast V-ATPases. Our recent findings showed that VHA-a3 targets to the tonoplast through a Rab5-mediated but Rab7-independent pathway, shedding new lights on the unconventional vacuolar trafficking route in plant cells.

Abstract (Browse 260)  |  References  |  Full Text HTML  |  Full Text PDF  |  Cited By       
Dynamic trafficking of membrane proteins is crucial for cells to function properly, not unlike a transportation network linking all locations within a city. Understanding regulators in these trafficking routes is thus an important topic. This study reveals a regulatory route through which the tonoplast-associated V-ATPase is transported in Arabidopsis.
An epiallele of rice AK1 affects photosynthetic capacity  
Author: Xiangjin Wei, Xianwei Song, Liya Wei, Shaoqing Tang, Jing Sun, Peisong Hu and Xiaofeng Cao
Journal of Integrative Plant Biology 2017 59(3): 158每163
Published Online: January 6, 2017
DOI: 10.1111/jipb.12518
      
    

Epigenetic gene variants, termed epialleles, can broaden genetic and phenotypic diversity in eukaryotes. Here, we identify a natural epiallele of OsAK1, which encodes a rice adenylate kinase. The Epi-ak1 plants show albino in young leaf and panicle with abnormal chloroplast structures. We found that no nucleotide sequence variation but hypermethylation at promoter region caused silencing of OsAK1 (Os08g01770) in Epi-ak1 plants. OsAK1 localizes to chloroplast and many genes associated with photosynthesis processes were downregulated in Epi-ak1. Thus, the work identified a novel rice epiallele caused by DNA methylation changes, shedding light on significant roles of DNA methylation on rice development.

Abstract (Browse 293)  |  References  |  Full Text HTML  |  Full Text PDF  |  Cited By       
A naturally epigenetic gene variant, which carries hypermethylated cytosines at promoter of OsAK1 (Os08g01770), was identified in rice. The hypermethylation causes silencing of this gene and leads to albino in young leaf and panicle, shedding light on significant roles of DNA methylation on rice development.
COR27 and COR28 encode nighttime repressors integrating Arabidopsis circadian clock and cold response  
Author: Peng Wang, Xuan Cui, Chunsheng Zhao, Liyan Shi, Guowei Zhang, Fenglong Sun, Xiaofeng Cao, Li Yuan, Qiguang Xie and Xiaodong Xu
Journal of Integrative Plant Biology 2017 59(2): 78每85
Published Online: December 19, 2016
DOI: 10.1111/jipb.12512
      
    

It was noted that circadian components function in plant adaptation to diurnal temperature cycles and freezing tolerance. Our genome-wide transcriptome analysis revealed that evening-phased COR27 and COR28 mainly repress the transcription of clock-associated evening genes PRR5, ELF4 and cold-responsive genes. Chromatin immunoprecipitation indicated that CCA1 is recruited to the site containing EE elements of COR27 and COR28 promoters in a temperature-dependent way. Further genetic analysis shows COR28 is essential for the circadian function of PRR9 and PRR7. Together, our results support a role of COR27 and COR28 as nighttime repressors integrating circadian clock and plant cold stress responses.

Abstract (Browse 335)  |  References  |  Full Text HTML  |  Full Text PDF  |  Cited By       
COR27 and COR28 repress the transcription of evening-phased clock genes and cold-responsive genes, which is responsible for maintaining circadian rhythm, plant freezing tolerance and flowering time control. CCA1 directly regulates COR27 and COR28 rhythmic expression in a temperature-dependent manner. This indicates the essential roles of COR27 and COR28 in coordinating circadian clock and cold-stress signaling networks.
Loss of algal Proton Gradient Regulation 5 increases reactive oxygen species scavenging and H2 evolution  
Author: Mei Chen, Jin Zhang, Lei Zhao, Jiale Xing, Lianwei Peng, Tingyun Kuang, Jean-David Rochaix and Fang Huang
Journal of Integrative Plant Biology 2016 58(12): 943每946
Published Online: October 20, 2016
DOI: 10.1111/jipb.12502
      
    

We have identified hpm91, a Chlamydomonas mutant lacking Proton Gradient Regulation5 (PGR5) capable of producing hydrogen (H2) for 25 days with more than 30-fold yield increase compared to wild type. Thus, hpm91 displays a higher capacity of H2 production than a previously characterized pgr5 mutant. Physiological and biochemical characterization of hpm91 reveal that the prolonged H2 production is due to enhanced stability of PSII, which correlates with increased reactive oxygen species (ROS) scavenging capacity during sulfur deprivation. This anti-ROS response appears to protect the photosynthetic electron transport chain from photo-oxidative damage and thereby ensures electron supply to the hydrogenase.

Abstract (Browse 318)  |  References  |  Full Text HTML  |  Full Text PDF  |  Cited By       
We identified and characterized a Chlamydomonas mutant (hpm91) lacking PGR5 which can produce H2 for 25 days with a more than 30-fold increase in yield as compared to wild type. This capacity exceeds that of another pgr5 mutant and qualifies hpm91 as the algal strain with the highest H2-photoproduction.
Pollen size strongly correlates with stigma depth among Pedicularis species  
Author: Xiang-Ping Wang, Wen-Bin Yu, Shi-Guo Sun and Shuang-Quan Huang
Journal of Integrative Plant Biology 2016 58(10): 818每821
Published Online: March 15, 2016
DOI: 10.1111/jipb.12477
      
    

Darwin proposed that pollen size should be positively correlated with stigma depth rather than style length among species given that pollen tubes first enter the stigma autotrophically, then grow through the style heterotrophically. However, studies often show a positive relationship between pollen size and style length. Five floral traits were observed to be correlated among 42 bumblebee-pollinated Pedicularis species (Orobanchaceae) in which stigmas are distinct from styles. The phylogenetic independent contrast analysis revealed that pollen grain volume was more strongly correlated with stigma depth than with style length, consistent with Darwin's functional hypothesis between pollen size and stigma depth.

Abstract (Browse 636)  |  References  |  Full Text HTML  |  Full Text PDF  |  Cited By       
It was often observed a positive correlation between pollen size and style length among different species. However, Darwin (1877) had proposed that pollen size should be positively correlated with stigma depth rather than style length, given that pollen tubes first enter the stigma autotrophically, thereafter grow through the style heterotrophically. We provide evidence in support of the Darwin*s hypothesis by surveying 42 Pedicularis species with the phylogenetic independent contrast analysis.
An exon skipping in a SEPALLATA-Like gene is associated with perturbed floral and fruits development in cucumber  
Author: Xin Wang, Dongli Gao, Jinjing Sun, Min Liu, Yaoyao Lun, Jianshu Zheng, Shenhao Wang, Qingzhi Cui, Xiaofeng Wang and Sanwen Huang
Journal of Integrative Plant Biology 2016 58(9): 766每771
Published Online: March 3, 2016
DOI: 10.1111/jipb.12472
      
    
We isolated a mutant showing perturbations in the development of male and female floral organs and fruits. Analysis of the single nucleotide polymorphisms from bulked F2 pools identified the causative variant occurring in Csa4G126690. Csa4G126690 shows high homology to Arabidopsis SEPALLATA2 (SEP2) thus being designated CsSEP2. The causative variant was located on the splicing site of CsSEP2, resulting in the skipping of exon 6 and abolishment of the transcriptional activity. Our data suggest that CsSEP2 is involved in the floral organ and fruits development by conferring transcriptional activity.
Abstract (Browse 601)  |  References  |  Full Text HTML  |  Full Text PDF  |  Cited By       
We isolated a mutant showing perturbations in the development of floral organs and fruits in cucumber. We further identified the causative variant occurring in CsSEP2 by whole genome re-sequencing of the mutant. The variant caused the skipping of exon 6 and abolishment of the transcriptional activity, thus perturbing floral organs and fruits development.
Shade-induced stem elongation in rice seedlings: Implication of tissue-specific phytohormone regulation  
Author: Huihui Liu, Chuanwei Yang and Lin Li
Journal of Integrative Plant Biology 2016 58(7): 614每617
Published Online: February 17, 2016
DOI: 10.1111/jipb.12468
      
    

A better understanding of shade avoidance syndrome (SAS) is an urgent need because of its effect on energy reallocation. Leverage-related mechanism in crops is of potential economic interest for agricultural applications. Here we report the SAS phenotype at tissue level rice seedlings. Tissue-specific RNA-sequencing indicates auxin plays different roles between coleoptile and the first leaf. Phenotypes of wild type treated by gibberellin and brassinosteroid biosynthesis inhibitors and of related mutants suggest these two hormones positively regulate SAS. Our work reveals the diversity of hormone responses in different organs and different species in shade conditions.

Abstract (Browse 753)  |  References  |  Full Text HTML  |  Full Text PDF  |  Cited By       
The authors grow rice seedlings in simulated shade which mimic the seedlings grown in high density, and characterize the phenotype and global transcriptome changes. This work suggests that hormone inhibitors, such as PAC, can help form compact and sturdy seedlings without compromising growth in paddy fields.
Mutation in the gene encoding 1-aminocyclopropane-1-carboxylate synthase 4 (CitACS4) led to andromonoecy in watermelon  
Author: Gaojie Ji, Jie Zhang, Haiying Zhang, Honghe Sun, Guoyi Gong, Jianting Shi, Shouwei Tian, Shaogui Guo, Yi Ren, Huolin Shen, Junping Gao and Yong Xu
Journal of Integrative Plant Biology 2016 58(9): 762每765
Published Online: February 3, 2016
DOI: 10.1111/jipb.12466
      
    

Although it has been reported previously that ethylene plays a critical role in sex determination in cucurbit species, how the andromonoecy that carries both the male and hermaphroditic flowers is determined in watermelon is still unknown. Here we showed that the watermelon gene 1-aminocyclopropane-1-carboxylate synthase 4 (CitACS4), expressed specifically in carpel primordia, determines the andromonoecy in watermelon. Among four single nucleotide polymorphism (SNPs) and one InDel identified in the coding region of CitACS4, the C364W mutation located in the conserved box 6 was co-segregated with andromonoecy. Enzymatic analyses showed that the C364W mutation caused a reduced activity in CitACS4. We believe that the reduced CitACS4 activity may hamper the programmed cell death in stamen primordia, leading to the formation of hermaphroditic flowers.

Abstract (Browse 633)  |  References  |  Full Text HTML  |  Full Text PDF  |  Cited By       
In this study, we showed that the watermelon gene 1-aminocyclopropane-1-carboxylate synthase 4 (CitACS4), expressed specifically in carpel primordia, determines the andromonoecy in watermelon. The C364W mutation of CitACS4 caused its reduced activity. We believe our results will be helpful to improve the breeding production in watermelon.
The wheat MYB-related transcription factor TaMYB72 promotes flowering in rice  
Author: Lichao Zhang, Guoxiang Liu, Jizeng Jia, Guangyao Zhao, Chuan Xia, Lina Zhang, Fu Li, Qiang Zhang, Chunhao Dong, Shuangcheng Gao, Longzhi Han, Xiuping Guo, Xin Zhang, Jinxia Wu, Xu Liu and Xiuying Kong
Journal of Integrative Plant Biology 2016 58(8): 701-704
Published Online: December 30, 2015
DOI: 10.1111/jipb.12461
      
    
Through large-scale transformation analyses, TaMYB72 was identified as a flowering time regulator in wheat. TaMYB72 is a MYB family transcription factor localized to the nucleus. Three TaMYB72 homologs, TaMYB72-A, TaMYB72-B and TaMYB72-D, cloned from hexaploid wheat were mapped to the short arm of the group 6 chromosomes. Under the long-day conditions, over-expression of the TaMYB72 in rice shortened the flowering time by approximately 12 d. Expression analyses suggest that TaMYB72 may function through up-regulation of florigen genes Hd3a and RFT1.

 

 

Abstract (Browse 801)  |  References  |  Full Text HTML  |  Full Text PDF  |  Cited By       
TaMYB72 has been identified as flowering time regulator in wheat. TaMYB72 encoded a MYB family transcription factor localized to the nucleus. Over-expression of TaMYB72 in rice shortened the flowering time by approximately 12 days. Expression analyses suggested that TaMYB72 may function through the up-regulation of rice florigen genes Hd3a and RFT1.
Are long corolla tubes in Pedicularis driven by pollinator selection?  
Author: Shuang-Quan Huang, Xiang-Ping Wang and Shi-Guo Sun
Journal of Integrative Plant Biology 2016 58(8): 698-700
Published Online: December 30, 2015
DOI: 10.1111/jipb.12460
      
    

The evolution of long corolla tubes has been hypothesized to be driven by long-tongued pollinators. Corolla tubes in Pedicularis species can be longer than 10 cm which may function as flower stalks to increase visual attractiveness to pollinators because these species provide no nectar and are pollinated by bumblebees. The corolla tube length was manipulated (shorter or longer) in two Pedicularis species in field to examine whether longer tubes are more attractive to pollinators and produce more seeds than short tubes. Our results did not support the pollinator attraction hypothesis, leaving the evolution of long tubes in Pedicularis remains mysterious.

Abstract (Browse 699)  |  References  |  Full Text HTML  |  Full Text PDF  |  Cited By       
The evolution of long corolla tubes in Pedicularis species seems to break a classic ※arms race§ model between plants and pollinators. Quantifying manipulated corolla tube length and fitness in two Pedicularis species indicated that longer tubes were not more attractive to pollinators with more seeds than short tubes.
Depletion of tyrosyl-DNA phosphodiesterase 1汐 (MtTdp1汐) affects transposon expression in Medicago truncatula  
Author: Maria Elisa Sabatini, Mattia Donà, Paola Leonetti, Andrea Minio, Massimo Delledonne, Daniela Carbonera, Massimo Confalonieri, Giorgio Giraffa and Alma Balestrazzi
Journal of Integrative Plant Biology 2016 58(7): 618每622
Published Online: December 23, 2015
DOI: 10.1111/jipb.12457
      
    

The role of plant tyrosyl-DNA phosphodiesterase 1α in genome stability is studied using a Medicago truncatula MtTdp1α-depleted line. Lack of MtTdp1α results in a 39% reduction of methylated cytosines as compared to control. RNA-Seq analyses revealed that 11 DNA transposons and 22 retrotransposons were differentially expressed in the Tdp1α-2a line. Among them all, DNA transposons (MuDR, hAT, DNA3-11_Mad) and seven retrotransposons (LTR (Long Terminal Repeat)/Gipsy, LTR/Copia, LTR and NonLTR/L1) were down-regulated, while the 15 retrotransposons were up-regulated. Results suggest that the occurrence of stress-responsive cis-elements as well as changes in the methylation pattern at the LTR promoters might be responsible for the enhanced retrotransposon transcription.

Abstract (Browse 621)  |  References  |  Full Text HTML  |  Full Text PDF  |  Cited By       
Long-distance nitrate signaling displays cytokinin dependent and independent branches  
Author: Sandrine Ruffel, Arthur Poitout, Gabriel Krouk, Gloria M. Coruzzi and Benoit Lacombe
Journal of Integrative Plant Biology 2016 58(3): 226每229
Published Online: December 1, 2015
DOI: 10.1111/jipb.12453
      
    

The long-distance signaling network allowing a plant to properly develop its root system is crucial to optimize root foraging in areas where nutrients are available. Cytokinin is an essential element of the systemic signaling network leading to the enhancement of lateral root proliferation in areas where nitrate is available. Here, we explore more precisely: (i) which particular traits of lateral root growth (density and length of emerged lateral roots) are the targets of systemic signaling in a context of heterogeneous nitrate supply; and (ii) if the systemic signaling depends only on cytokinin or on a combination of several signalings.

Abstract (Browse 675)  |  References  |  Full Text HTML  |  Full Text PDF  |  Cited By       
Heterogeneous nutrient availability is frequent during plant life cycle. Therefore, long-distance communication is crucial to properly tune root development according to local nutrient availability and whole-plant needs. Here, we show that multiple traits of root development are the targets of nitrate long-distance signaling, dependently or independently of cytokinin biosynthesis.
Cellulose synthesis genes CESA6 and CSI1 are important for salt stress tolerance in Arabidopsis  
Author: Shuang-Shuang Zhang, Le Sun, Xinran Dong, Sun-Jie Lu, Weidong Tian and Jian-Xiang Liu
Journal of Integrative Plant Biology 2016 58(7): 623每626
Published Online: October 27, 2015
DOI: 10.1111/jipb.12442
Abstract (Browse 925)  |  References  |  Full Text HTML  |  Full Text PDF  |  Cited By       
Two salt hypersensitive mutants she1 and she2 were identified through genetic screening. SHE1 encodes a cellulose synthase CESA6 while SHE2 encodes a cellulose synthase-interactive protein CSI1. Both of them are involved in cellulose deposition. Our results demonstrated that the sustained cellulose synthesis is important for salt stress tolerance in Arabidopsis.
Active role of small peptides in Arabidopsis reproduction: Expression evidence  
Author: Qingpei Huang, Thomas Dresselhaus, Hongya Gu and Li-Jia Qu
Journal of Integrative Plant Biology 2015 57(6): 518每521
Published Online: March 31, 2015
DOI: 10.1111/jipb.12356
Abstract (Browse 806)  |  References  |  Full Text HTML  |  Full Text PDF  |  Cited By       
Large number of small peptides exhibit gametophyte-specific and dynamic expression profiles along the ovule developmental axis, implicating their vital function in plant reproduction.

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