February 2014, Volume 56 Issue 2, Pages 106每188.


Cover Caption: Farinose Flavone in Frost Protection
About the cover: During cold seasons, fairy primroses secrete various amounts of farinose flavone through specialized trichomes. In this issue, Isshiki et al. (pp. 181每188) query the role of flavone in frost protection, and observed that the ice nucleation temperatures closely correlated with amounts of flavone produced by selected cultivars, and exogenous application of flavone efficiently protected leaves and buds from freezing.

 

          Minireview
Insight into the mode of action of 2,4-dichlorophenoxyacetic acid (2,4-D) as an herbicide  
Author: Yaling Song
Journal of Integrative Plant Biology 2014 56(2): 106每113
Published Online: January 24, 2014
DOI: 10.1111/jipb.12131
      
    

2,4-Dichlorophenoxyacetic acid (2,4-D) was the first synthetic herbicide to be commercially developed and has commonly been used as a broadleaf herbicide for over 60 years. It is a selective herbicide that kills dicots without affecting monocots and mimics natural auxin at the molecular level. Physiological responses of dicots sensitive to auxinic herbicides include abnormal growth, senescence, and plant death. The identification of auxin receptors, auxin transport carriers, transcription factors response to auxin, and cross-talk among phytohormones have shed light on the molecular action mode of 2,4-D as a herbicide. Here, the molecular action mode of 2,4-D is highlighted according to the latest findings, emphasizing the physiological process, perception, and signal transduction under herbicide treatment.

Song Y (2014) Insight into the mode of action of 2,4坼dichlorophenoxyacetic acid (2,4坼D) as an herbicide. J Integr Plant Biol 56: 106–113. doi: 10.1111/jipb.12131

Abstract (Browse 959)  |  References  |  Full Text HTML  |  Full Text PDF  |  Cited By       
Improvement of plant abiotic stress tolerance through modulation of the polyamine pathway  
Author: Haitao Shi and Zhulong Chan
Journal of Integrative Plant Biology 2014 56(2): 114每121
Published Online: January 8, 2014
DOI: 10.1111/jipb.12128
      
    
Polyamines (mainly putrescine (Put), spermidine (Spd), and spermine (Spm)) have been widely found in a range of physiological processes and in almost all diverse environmental stresses. In various plant species, abiotic stresses modulated the accumulation of polyamines and related gene expression. Studies using loss-of-function mutants and transgenic overexpression plants modulating polyamine metabolic pathways confirmed protective roles of polyamines during plant abiotic stress responses, and indicated the possibility to improve plant tolerance through genetic manipulation of the polyamine pathway. Additionally, putative mechanisms of polyamines involved in plant abiotic stress tolerance were thoroughly discussed and crosstalks among polyamine, abscisic acid, and nitric oxide in plant responses to abiotic stress were emphasized. Special attention was paid to the interaction between polyamine and reactive oxygen species, ion channels, amino acid and carbon metabolism, and other adaptive responses. Further studies are needed to elucidate the polyamine signaling pathway, especially polyamine-regulated downstream targets and the connections between polyamines and other stress responsive molecules.

Shi H, Chan Z (2014) Improvement of plant abiotic stress tolerance through modulation of the polyamine pathway. J Integr Plant Biol 56: 114–121. doi: 10.1111/jipb.12128

Abstract (Browse 1024)  |  References  |  Full Text HTML  |  Full Text PDF  |  Cited By       
          Functional Omics and Systems Biology
Why mosaic? Gene expression profiling of African cassava mosaic virus-infected cassava reveals the effect of chlorophyll degradation on symptom development
Author: Jiao Liu, Jun Yang, Huiping Bi and Peng Zhang
Journal of Integrative Plant Biology 2014 56(2): 122每132
Published Online: January 29, 2014
DOI: 10.1111/jipb.12133
      
    

Cassava mosaic disease, caused by cassava begomoviruses, is the most serious disease for cassava in Africa. However, the pathogenesis of this disease is poorly understood. We employed high throughput digital gene expression profiling based on the Illumina Solexa sequencing technology to investigate the global transcriptional response of cassava to African cassava mosaic virus infection. We found that 3,210 genes were differentially expressed in virus-infected cassava leaves. Gene ontology term and Kyoto Encyclopedia of Genes and Genomes pathway analysis indicated that genes implicated in photosynthesis were most affected, consistent with the chlorotic symptoms observed in infected leaves. The upregulation of chlorophyll degradation genes, including the genes encoding chlorophyllase, pheophytinase, and pheophorbide a oxygenase, and downregulation of genes encoding the major apoproteins in light-harvesting complex II were confirmed by qRT-PCR. These findings, together with the reduction of chlorophyll b content and fewer grana stacks in the infected leaf cells, reveal that the degradation of chlorophyll plays an important role in African cassava mosaic virus symptom development. This study will provide a road map for future investigations into viral pathogenesis.

Liu J, Yang J, Bi H, Zhang P (2014) Why mosaic? Gene expression profiling of African cassava mosaic virus坼infected cassava reveals the effect of chlorophyll degradation on symptom development. J Integr Plant Biol 56: 122–132. doi: 10.1111/jipb.12133

Abstract (Browse 836)  |  References  |  Full Text HTML  |  Full Text PDF  |  Cited By       
          Molecular Ecology and Evolution
Small auxin upregulated RNA (SAUR) gene family in maize: Identification, evolution, and its phylogenetic comparison with Arabidopsis, rice, and sorghum
Author: Yuzhu Chen, Xi Hao and Jun Cao
Journal of Integrative Plant Biology 2014 56(2): 133每150
Published Online: January 29, 2014
DOI: 10.1111/jipb.12127
      
    

Small auxin-up RNAs (SAURs) are the early auxin-responsive genes represented by a large multigene family in plants. Here, we identified 79 SAUR gene family members from maize (Zea mays subsp. mays) by a reiterative database search and manual annotation. Phylogenetic analysis indicated that the SAUR proteins from Arabidopsis, rice, sorghum, and maize had divided into 16 groups. These genes were non-randomly distributed across the maize chromosomes, and segmental duplication and tandem duplication contributed to the expansion of the maize SAUR gene family. Synteny analysis established orthology relationships and functional linkages between SAUR genes in maize and sorghum genomes. We also found that the auxin-responsive elements were conserved in the upstream sequences of maize SAUR members. Selection analyses identified some significant site-specific constraints acted on most SAUR paralogs. Expression profiles based on microarray data have provided insights into the possible functional divergence among members of the SAUR gene family. Quantitative real-time PCR analysis indicated that some of the 10 randomly selected ZmSAUR genes could be induced at least in maize shoot or root tissue tested. The results reveal a comprehensive overview of the maize SAUR gene family and may pave the way for deciphering their function during plant development.

Chen Y, Hao X, Cao J (2014) Small auxin up坼regulated RNA (SAUR) gene family in maize: Identification, evolution, and its phylogenetic comparison with Arabidopsis, rice and sorghum. J Integr Plant Biol 56: 133–150. doi: 10.1111/jipb.12127

Abstract (Browse 744)  |  References  |  Full Text HTML  |  Full Text PDF  |  Cited By       
Characterization of a novel DUF1618 gene family in rice
Author: Lan Wang, Rongxin Shen, Le-Tian Chen and Yao-Guang Liu
Journal of Integrative Plant Biology 2014 56(2): 151每158
Published Online: January 23, 2014
DOI: 10.1111/jipb.12130
      
    

Domain of unknown function (DUF) proteins represent a number of gene families that encode functionally uncharacterized proteins in eukaryotes. For example, DUF1618 family members in plants possess a 56–199-amino acid conserved domain and this family has not been described previously. Here, we report the characterization of 121 DUF1618 genes identified in the rice genome. Based on phylogenetic analysis, the rice DUF1618 family was divided into two major groups, each group consisting of two clades. Most DUF1618 genes with close phylogenetic relationships are located in gene clusters on the chromosomes, indicating that gene duplications increased the number of DUF1618 genes. A search for DUF1618 genes in genomic and/or expressed sequence tag databases for 35 other plant species showed that DUF1618 genes are only present in several monocot plants, suggesting that DUF1618 is a new gene family that originated after the dicot–monocot divergence. Based on public microarray databases, most rice DUF1618 genes are expressed at relatively low levels. Further experimental analysis showed that the transcriptional levels of some DUF1618 genes varied in different cultivars, and some responded to stress and hormone conditions, suggesting their important roles for development and fitness in rice (Oryza sativa L.).

Wang L, Shen R, Chen LT, Liu YG (2014) Characterization of a novel DUF1618 gene family in rice. J Integr Plant Biol 56: 151–158. doi: 10.1111/jipb.12130

Abstract (Browse 927)  |  References  |  Full Text HTML  |  Full Text PDF  |  Cited By       
          Molecular Physiology
Diversity characterization and association analysis of agronomic traits in a Chinese peanut (Arachis hypogaea L.) mini-core collection
Author: Huifang Jiang, Li Huang, Xiaoping Ren, Yuning Chen, Xiaojing Zhou, Youlin Xia, Jiaquan Huang, Yong Lei, Liying Yan, Liyun Wan and Boshou Liao
Journal of Integrative Plant Biology 2014 56(2): 159每169
Published Online: January 23, 2014
DOI: 10.1111/jipb.12132
      
    

Association mapping is a powerful approach for exploring the molecular basis of phenotypic variations in plants. A peanut (Arachis hypogaea L.) mini-core collection in China comprising 298 accessions was genotyped using 109 simple sequence repeat (SSR) markers, which identified 554 SSR alleles and phenotyped for 15 agronomic traits in three different environments, exhibiting abundant genetic and phenotypic diversity within the panel. A model-based structure analysis assigned all accessions to three groups. Most of the accessions had the relative kinship of less than 0.05, indicating that there were no or weak relationships between accessions of the mini-core collection. For 15 agronomic traits in the peanut panel, generally the Q + K model exhibited the best performance to eliminate the false associated positives compared to the Q model and the general linear model-simple model. In total, 89 SSR alleles were identified to be associated with 15 agronomic traits of three environments by the Q + K model-based association analysis. Of these, eight alleles were repeatedly detected in two or three environments, and 15 alleles were commonly detected to be associated with multiple agronomic traits. Simple sequence repeat allelic effects confirmed significant differences between different genotypes of these repeatedly detected markers. Our results demonstrate the great potential of integrating the association analysis and marker-assisted breeding by utilizing the peanut mini-core collection.

Jiang H, Huang L, Ren X, Chen Y, Zhou X, Xia Y, Huang J, Lei Y, Yan L, Wan L, Liao B (2014) Diversity characterization and association analysis of agronomic traits in a Chinese peanut (Arachis hypogaea L.)
mini坼core collection. J Integr Plant Biol 56: 159–169. doi: 10.1111/jipb.12132

Abstract (Browse 855)  |  References  |  Full Text HTML  |  Full Text PDF  |  Cited By       
Two hydroxypyruvate reductases encoded by OsHPR1 and OsHPR2 are involved in photorespiratory metabolism in rice
Author: Nenghui Ye, Guozhen Yang, Yan Chen, Chan Zhang, Jianhua Zhang and Xinxiang Peng
Journal of Integrative Plant Biology 2014 56(2): 170每180
Published Online: January 8, 2014
DOI: 10.1111/jipb.12125
      
    

Mutations in the photorespiration pathway display a lethal phenotype in atmospheric air, which can be fully recovered by elevated CO2. An exception is that mutants of peroxisomal hydroxypyruvate reductase (HPR1) do not have this phenotype, indicating the presence of cytosolic bypass in the photorespiration pathway. In this study, we constructed overexpression of the OsHPR1 gene and RNA interference plants of OsHPR1 and OsHPR2 genes in rice (Oryza sativa L. cv. Zhonghua 11). Results from reverse transcription-polymerase chain reaction (RT-PCR), Western blot, and enzyme assays showed that HPR1 activity changed significantly in corresponding transgenic lines without any effect on HPR2 activity, which is the same for HPR2. However, metabolite analysis and the serine glyoxylate aminotransferase (SGAT) activity assay showed that the metabolite flux of photorespiration was disturbed in RNAi lines of both HPR genes. Furthermore, HPR1 and HPR2 proteins were located to the peroxisome and cytosol, respectively, by transient expression experiment. Double mutant hpr1 × hpr2 was generated by crossing individual mutant of hpr1 and hpr2. The phenotypes of all transgenic lines were determined in ambient air and CO2-elevated air. The phenotype typical of photorespiration mutants was observed only where activity of both HPR1 and HPR2 were downregulated in the same line. These findings demonstrate that two hydroxypyruvate reductases encoded by OsHPR1 and OsHPR2 are involved in photorespiratory metabolism in rice.

Ye N, Yang G, Chen Y, Zhang C, Zhang J, Peng X (2014) Two hydroxypyruvate reductases encoded by OsHPR1 and OsHPR2 are involved in photorespiratory metabolism in rice. J Integr Plant Biol 56: 170–180. doi: 10.1111/jipb.12125

Abstract (Browse 861)  |  References  |  Full Text HTML  |  Full Text PDF  |  Cited By       
          Plant-environmental Interactions
Farinose flavonoids are associated with high freezing tolerance in fairy primrose (Primula malacoides) plants
Author: Ryutaro Isshiki, Ivan Galis and Shigemi Tanakamaru
Journal of Integrative Plant Biology 2014 56(2): 181每188
Published Online: January 29, 2014
DOI: 10.1111/jipb.12145
      
    

The deposition of surface (farinose) flavonoids on aerial parts of some Primula species is a well-documented but poorly understood phenomenon. Here, we show that flavonoid deposition on the leaves and winter buds may contribute strongly to preventing freezing damage in these plants. The ice nucleation temperature of fairy primrose (Primula malacoides) leaves covered with natural flavone was approximately 6 °C lower compared to those that had their flavone artificially removed. Additionally, farinose flavonoids on the leaves reduced subsequent electrolyte leakage (EL) from the cells exposed to freezing temperatures. Interestingly, exogenous application of flavone at 4 mg/g fresh weight to P. malacoides leaves, which had the original flavone mechanically removed, restored freezing tolerance, and diminished EL from the cells to pretreatment values. Our results suggest that farinose flavonoids may function as mediators of freezing tolerance in P. malacoides, and exogenous application of flavone could be used to reduce freezing damage during sudden but predictable frost events in other plant species.

Isshiki R, Galis I, Tanakamaru S (2014) Farinose flavonoids are associated with high freezing tolerance in fairy primrose (Primula malacoides) plants. J Integr Plant Biol 56: 181–188. doi: 10.1111/jipb. 12145

Abstract (Browse 683)  |  References  |  Full Text HTML  |  Full Text PDF  |  Cited By       
 

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