Latest Accepted Articles

  Special Issue: Genomics-assisted Germplasm Improvement in Rice
OsIDD2, a zinc finger and INDETERMINATE DOMAIN protein regulates secondary cell wall formation
Author: Peng Huang, Hideki Yoshida, Kenji Yano, Shunsuke Kinoshita, Kyosuke Kawai, Eriko Koketsu, Masako Hattori, Sayaka Takehara, Ji Huang, Ko Hirano, Reynante Lacsamana Ordonio, Makoto Matsuoka and Miyako Ueguchi-Tanaka
Received: February 8, 2017         Accepted: May 29, 2017
Online Date: June 2, 2017
DOI: 10.1111/jipb.12557
                     
      
    

Previously, we found 123 transcription factors (TFs) as candidate regulators of secondary cell wall (SCW) formation in rice by using phylogenetic and co-expression network analyses. Among them, we examined in this work the role of OsIDD2, a zinc finger and indeterminate domain (IDD) family TF. Its overexpressors showed dwarfism, fragile leaves, and decreased lignin content, which are typical phenotypes of plants defective in SCW formation, whereas its knockout plants showed slightly increased lignin content. The RNA-seq and qRT-PCR analyses confirmed that some lignin biosynthetic genes were downregulated in the OsIDD2-overexpressing plants, and revealed the same case for other genes involved in cellulose synthesis and sucrose metabolism. The transient expression assay using rice protoplasts revealed that OsIDD2 negatively regulates the transcription of genes involved in lignin biosynthesis, cinnamyl alcohol dehydrogenase 2 and 3 (CAD2 and 3), and sucrose metabolism, sucrose synthase 5 (SUS5), whereas an AlphaScreen assay, which can detect the interaction between TFs and their target DNA sequences, directly confirmed the interaction between OsIDD2 and the target sequences located in the promoter regions of CAD2 and CAD3. Based on these observations, we conclude that OsIDD2 is negatively involved in SCW formation and other biological events by downregulating its target genes.

Abstract (Browse 39)   |   Full Text
  Special Issue: Sexual Plant Reproduction
ZYGOTE-ARREST 3 that encodes the tRNA ligase is essential for zygote division in Arabidopsis
Author: Ke-Jin Yang, Lei Guo, Xiu-Li Hou, Hua-Qin Gong and Chun-Ming Liu
Received: May 25, 2017         Accepted: June 16, 2017
Online Date: June 20, 2017
DOI: 10.1111/jipb.12561
                     
      
    

In sexual organisms, division of the zygote initiates a new life cycle. Although several genes involved in zygote division are known in plants, how the zygote is activated to start embryogenesis remains elusive. Here, we showed that a mutation in ZYGOTE-ARREST 3 (ZYG3) in Arabidopsis led to a tight zygote-lethal phenotype. Map-based cloning revealed that ZYG3 encodes the tRNA ligase AtRNL, which is a single-copy gene in the Arabidopsis genome. Expression analyses showed that AtRNL is expressed throughout zygotic embryogenesis, and in meristematic tissues. Using pAtRNL::cAtRNL-sYFP-complemented zyg3/zyg3 plants, we showed that AtRNL is localized exclusively in the cytoplasm, suggesting that tRNA splicing occurs primarily in the cytoplasm. Analyses using partially rescued embryos showed that mutation in AtRNL compromised splicing of intron-containing tRNA. Mutations of two tRNA endonuclease genes, SEN1 and SEN2, also led to a zygote-lethal phenotype. These results together suggest that tRNA splicing is critical for initiating zygote division in Arabidopsis.

Abstract (Browse 14)   |   Full Text
Arabidopsis adaptor protein 1G is critical for pollen development
Author: Chong Feng, Jia-Gang Wang, Hai-Hong Liu, Sha Li and Yan Zhang
Received: April 12, 2017         Accepted: May 22, 2017
Online Date: 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 with dynamic remodeling of vacuoles through fission and fusion, disruption of which often compromises pollen viability. We previously reported that the Υ 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 ultra-structural 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 76)   |   Full Text
  Letters to the Editor
Arabidopsis TOR signaling is essential for sugar-regulated callus formation
Author: Kyounghee Lee and Pil Joon Seo
Received: May 10, 2017         Accepted: June 16, 2017
Online Date: 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 found 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 20)   |   Full Text
Mutation in a novel gene SMALL AND CORDATE LEAF 1 affects leaf morhology in cucumber
Author: Dongli Gao, Chunzhi Zhang, Shu Zhang, Bowen Hu, Shenhao Wang, Zhonghua Zhang and Sanwen Huang
Received: May 12, 2017         Accepted: June 7, 2017
Online Date: 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, scl1 mutant had less number of epidermal pavement cells. A single nucleotide polymorphism was associated with the 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 28)   |   Full Text
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
Received: April 7, 2017         Accepted: April 28, 2017
Online Date: 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 remains 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 102)   |   Full Text
  Cell and Developmental Biology
HP30-2, a mitochondrial PRAT protein for import of signal sequence-less precursor proteins in Arabidopsis thaliana
Author: Claudia Rossig, John Gray, Oscar Valdes, Sachin Rustgi, Diter von Wettstein, Christiane Reinbothe and Steffen Reinbothe
Received: February 16, 2017         Accepted: May 19, 2017
Online Date: May 22, 2017
DOI: 10.1111/jipb.12555
                     
      
    

Chloroplasts and mitochondria contain a family of putative preprotein and amino acid transporters designated PRAT. Here, we analyzed the role of two previously characterized PRAT protein family member, encoded by At3g49560 (HP30) and At5g24650 (HP30-2), in planta using a combination of genetic, cell biological and biochemical approaches. Expression studies and GFP tagging identified HP30-2 both in chloroplasts and mitochondria, whereas HP30 was located exclusively in chloroplasts. Biochemical evidence was obtained for an association of mitochondrial HP30-2 with two distinct protein complexes, one containing the inner membrane translocase TIM22 and the other containing an alternative NAD(P)H dehydrogenase subunit (NDC1) implicated in a respiratory complex 1-like electron transport chain. Through its association with TIM22, HP30-2 is involved in the uptake of carrier proteins and other, hydrophobic membrane proteins lacking cleavable NH2-terminal presequences, whereas HP30-2's interaction with NDC1 may permit controlling mitochondrial biogenesis and activity.

Abstract (Browse 57)   |   Full Text
  Plant-environmental Interactions
Unfolded protein response activation compensates ER-associated degradation deficiency in Arabidopsis
Author: Qingliang Li, Hai Wei, Lijing Liu, Xiaoyuan Yang, Xiansheng Zhang and Qi Xie
Received: February 17, 2017         Accepted: April 10, 2017
Online Date: April 18, 2017
DOI: 10.1111/jipb.12544
                     
      
    

Abiotic stresses often disrupt protein folding and induce endoplasmic reticulum (ER) stress. There is a sophisticated ER quality control (ERQC) system to mitigate the effects of malfunctioning proteins and maintain ER homeostasis. The accumulation of misfolded proteins in the ER activates the unfolded protein response (UPR) to enhance ER protein folding and the degradation of misfolded proteins mediate by ER-associated degradation (ERAD). That ERQC reduces abiotic stress damage has been well studied in mammals and yeast. However, in plants, both ERAD and UPR have been studied separately and found to be critical for plant abiotic stress tolerance. In this study, we discovered that UPR-associated transcription factors AtbZIP17, AtbZIP28 and AtbZIP60 responded to tunicamycin (TM) and NaCl induced ER stress and subsequently enhanced Arabidopsis thaliana abiotic stress tolerance. They regulated the expression level of ER chaperones and the HRD1-complex components. Moreover, overexpression of AtbZIP17, AtbZIP28 and AtbZIP60 could restore stress tolerance via ERAD in the HRD1-complex mutant hrd3a-2, which suggested that UPR and ERAD have an interactive mechanism in Arabidopsis.

Abstract (Browse 83)   |   Full Text
  Metabolism and Biochemistry
Phenolic metabolism and molecular mass distribution of polysaccharides in cellulose-deficient maize cells
Author: Mar®™a de Castro, Romina Mart®™nez-Rubio, Jos®¶ Luis Acebes, Antonio Encina, Stephen C. Fry and Pen®¶lope Garc®™a-Angulo
Received: March 30, 2017         Accepted: April 21, 2017
Online Date: May 5, 2017
DOI: 10.1111/jipb.12549
                     
      
    

As a consequence of the habituation to low levels of dichlobenil (DCB), cultured maize cells presented an altered hemicellulose cell fate with a lower proportion of strongly wall-bound hemicelluloses and an increase in soluble extracellular polymers released into the culture medium. The aim of this study was to investigate the relative molecular mass distributions of polysaccharides as well as phenolic metabolism in cells habituated to low levels of DCB (1.5 uM). Generally, cell wall bound hemicelluloses and sloughed polymers from habituated cells were more homogeneously sized and had a lower weight-average relative molecular mass. In addition, polysaccharides underwent massive cross-linking after being secreted into the cell wall, but this cross-linking was less pronounced in habituated cells than in non-habituated ones. However, when relativized, ferulic acid and p-coumaric acid contents were higher in this habituated cell line. Feasibly, cells habituated to low levels of DCB synthesized molecules with a lower weight-average relative molecular mass, although cross-linked, as a part of their strategy to compensate for the lack of cellulose.

Abstract (Browse 64)   |   Full Text
  Molecular Ecology and Evolution
The circadian clock component, LHY, tells a plant when to respond photosynthetically to light in nature
Author: Youngsung Joo, Variluska Fragoso, Felipe Yon, Ian T. Baldwin and Sang-Gyu Kim
Received: January 25, 2016         Accepted: April 18, 2017
Online Date: April 21, 2017
DOI: 10.1111/jipb.12547
                     
      
    

The circadian clock is known to increase plant growth and fitness, and thought to prepare plants for photosynthesis at dawn and dusk; whether this happens in nature was unknown. We transformed the native tobacco, Nicotiana attenuata to silence two core clock components, NaLHY (irLHY) and NaTOC1 (irTOC1). We characterized growth and light-and dark-adapted photosynthetic rates (Ac) throughout a 24 h day in empty vector-transformed (EV), irLHY, and irTOC1 plants in the field, and in NaPhyA-and NaPhyB1-silenced plants in the glasshouse. The growth rates of irLHY plants were lower than those of EV plants in the field. While irLHY plants reduced Ac earlier at dusk, no differences between irLHY and EV plants were observed at dawn in the field. irLHY, but not EV plants, responded to light in the night by rapidly increasing Ac. Under controlled conditions, EV plants rapidly increased Ac in the day compared to dark-adapted plants at night; irLHY plants lost these time-dependent responses. The role of NaLHY in gating photosynthesis is independent of the light-dependent reactions and red light perceived by NaPhyA, but not NaPhyB1. In summary, the circadian clock allows plants not to respond photosynthetically to light at night by anticipating and gating red light-mediated in native tobacco.

Abstract (Browse 102)   |   Full Text
  Invited Expert Review
Engineering crop nutrient efficiency for sustainable agriculture
Author: Liyu Chen and Hong Liao
Received: February 27, 2017         Accepted: June 6, 2017
Online Date: June 10, 2017
DOI: 10.1111/jipb.12559
                     
      
    

Increasing crop yields can provide food, animal feed, bioenergy feedstocks, and biomaterials to meet increasing global demand; however, the methods used to increase yield can negatively affect sustainability. For example, application of excess fertilizer can generate and maintain high yields but also increases input costs and contributes to environmental damage through eutrophication, soil acidification, and air pollution. Improving crop nutrient efficiency can improve agricultural sustainability by increasing yield while decreasing input costs and harmful environmental effects. Here, we review the mechanisms of nutrient efficiency (primarily for nitrogen, phosphorus, potassium, and iron) and breeding strategies for improving this trait, along with the role of regulation of gene expression in enhancing crop nutrient efficiency to increase yields. We focus on the importance of root system architecture to improve nutrient acquisition efficiency, as well as the contributions of mineral translocation, remobilization, and metabolic efficiency to nutrient utilization efficiency.

Abstract (Browse 45)   |   Full Text

PROMOTIONS

    Photo Gallery
Scan with iPhone or iPad to view JIPB online
Scan using WeChat with your smartphone to view JIPB online
Editorial Office, Journal of Integrative Plant Biology, Institute of Botany, CAS
No. 20 Nanxincun, Xiangshan, Beijing 100093, China
Tel: +86 10 6283 6133 Fax: +86 10 8259 2636 E-mail: jipb@ibcas.ac.cn

Copyright © 2017 by the Institute of Botany, the Chinese Academy of Sciences
Online ISSN: 1744-7909 Print ISSN: 1672-9072 CN: 11-5067/Q