January 1900, Volume 待分类 Issue 待分类

 

          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
Journal of Integrative Plant Biology 1900 待分类(待分类): 1-15
Published Online: 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 quantitative reverse transcription polymerase chain reaction 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 172)  |  References  |  Full Text HTML  |  Full Text PDF  |  Cited By       
Ectopic expression of fungal EcGDH improves nitrogen assimilation and grain yield in rice
Author: Dongying Tang, Yuchong Peng, Jianzhong Lin, Changqing Du, Yuanzhu Yang, Dan Wang, Cong Liu, Lu Yan, Xiaoying Zhao, Xia Li, Liangbi Chen and Xuanming Liu
Journal of Integrative Plant Biology 1900 待分类(待分类): 1-5
Published Online: January 6, 2017
DOI: 10.1111/jipb.12519
      
    

NADP(H)-dependent glutamate dehydrogenases (GDH) in lower organisms have stronger ammonium affinity than those in higher plants. Here we report that transgenic rice overexpressing the EcGDH from Eurotium cheralieri exhibited significantly enhanced aminating activities. Hydroponic and field tests showed that nitrogen assimilation efficiency and grain yields were markedly increased in these transgenic plants, especially at the low nitrogen conditions. These results suggest that EcGDH may have potential to be used to improve nitrogen assimilation and grain yield in rice.

Abstract (Browse 377)  |  References  |  Full Text HTML  |  Full Text PDF  |  Cited By       
QTL editing confers opposing yield performance in different rice varieties
Author: Lan Shen, Chun Wang, Yaping Fu, Junjie Wang, Qing Liu, Xiaoming Zhang, Changjie Yan, Qian Qian and Kejian Wang
Journal of Integrative Plant Biology 1900 待分类(待分类): 1-4
Published Online: September 15, 2016
DOI: 10.1111/jipb.12501
      
    

Grain yield is one of the most important and complex trait for genetic improvement in crops; it is known to be controlled by a number of genes known as quantitative trait loci (QTLs). In the past decade, many yield-contributing QTLs have been identified in crops. However, it remains unclear whether those QTLs confer the same yield performance in different genetic backgrounds. Here, we performed CRISPR/Cas9-mediated QTL editing in five widely-cultivated rice varieties and revealed that the same QTL can have diverse, even opposing, effects on grain yield in different genetic backgrounds.

Abstract (Browse 446)  |  References  |  Full Text HTML  |  Full Text PDF  |  Cited By       
          Letter 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
Journal of Integrative Plant Biology 1900 待分类(待分类): 1-7
Published Online: August 26, 2017
DOI: 10.1111/jipb.12593
      
    

When herbivores attack, plants specifically reconfigure their metabolism. Herbivory on the wild tobacco Nicotiana attenuata strongly induces the R2R3 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 73)  |  References  |  Full Text HTML  |  Full Text PDF  |  Cited By       
          Plant-abiotic Interactions
Potassium channel AKT1 is involved in the auxin-mediated root growth inhibition in Arabidopsis response to low K+ stress
Author: Juan Li, Wei-Hua Wu and Yi Wang
Journal of Integrative Plant Biology 1900 待分类(待分类): 1-16
Published Online: August 7, 2017
DOI: 10.1111/jipb.12575
      
    

The changes in external K+ concentration affect plant root growth. However, the molecular mechanism for perceiving a K+ signal to modulate root growth remains unknown. It is hypothesized that the K+ channel AKT1 is involved in low K+ sensing in the Arabidopsis root and subsequent regulation of root growth. Along with the decline of external K+ concentration, the primary root growth of wild-type plants was gradually inhibited. However, the primary root of the akt1 mutant could still grow under low K+ (LK) conditions. Application of NAA inhibited akt1 root growth, but promoted wild-type root growth under LK conditions. By using the ProDR5:GFP and ProPIN1:PIN1-GFP lines, we found that LK treatment reduced auxin accumulation in wild-type root tips by degrading PIN1 proteins, which did not occur in the akt1 mutant. The LK-induced PIN1 degradation may be due to the inhibition of vesicle trafficking of PIN1 proteins. In conclusion, our findings indicate that AKT1 is required for an Arabidopsis response to changes in external K+, and subsequent regulation of K+-dependent root growth by modulating PIN1 degradation and auxin redistribution in the root.

Abstract (Browse 84)  |  References  |  Full Text HTML  |  Full Text PDF  |  Cited By       
          Cell and Developmental Biology
AGO18b negatively regulates determinacy of spikelet meristems on the tassel central spike in maize
Author: Wei Sun, Xiaoli Xiang, Lihong Zhai, Dan Zhang, Zheng Cao, Lei Liu and Zuxin Zhang
Journal of Integrative Plant Biology 1900 待分类(待分类): 1-14
Published Online: September 6, 2017
DOI: 10.1111/jipb.12596
      
    

The maize tassel represents an indeterminate male inflorescence. The number of primordia that a given inflorescence meristem produces is related to its determinacy, i.e., capacity for continued meristem activity. Transcription factors (TFs) controlling determinacy in tassel axillary meristems are well studied in maize, and small RNAs are known to influence tassel development by repressing targets, including tassel-related TFs. As core components of the RNA-inducible silence complex (RISC), Argonaute (AGO) proteins are required for small RNA-mediated repression. Here, we characterized the biological function of AGO18b, a tassel-enriched AGO. The abundance of AGO18b transcripts gradually increased during tassel development from inception to gametogenesis and were enriched in the inflorescence meristem and axillary meristems of the tassel. Repressing AGO18b expression resulted in more spikelets, which contributed to a longer central spike of the tassel. Additionally, the transcripts of several HD-ZIP III TFs that were canonical targets of microRNA166 (miR166) accumulated in the AGO18b-repressed lines. We propose that AGO18b is a negative regulator of the determinacy of inflorescence and axillary meristems, and that it acts by interacting with the miR166-HD-ZIP III TF regulatory pathway.

Abstract (Browse 51)  |  References  |  Full Text HTML  |  Full Text PDF  |  Cited By       
Arabidopsis EXO70A1 recruits Patellin3 to the cell membrane independent of its role as an exocyst subunit
Author: Chengyun Wu, Lu Tan, Max van Hooren, Xiaoyun Tan, Feng Liu, Yan Li, Yanxue Zhao, Bingxuan Li, Qingchen Rui, Teun Munnik and Yiqun Bao
Journal of Integrative Plant Biology 1900 待分类(待分类): 1-15
Published Online: August 16, 2017
DOI: 10.1111/jipb.12578
      
    

The exocyst is a well-known complex which tethers vesicles at the cell membrane before fusion. Whether an individual subunit can execute a unique function is largely unknown. Using yeast-two-hybrid (Y2H) analysis, we found that EXO70A1 interacted with the GOLD domain of Patellin3 (PATL3). The direct EXO70A1-PATL3 interaction was supported by in vitro and in vivo experiments. In Arabidopsis, PATL3-GFP colocalized with EXO70A1 predominantly at the cell membrane, and PATL3 localization was insensitive to BFA and TryA23. Remarkably, in the exo70a1 mutant, PATL3 proteins accumulated as punctate structures within the cytosol, which did not colocalize with several endomembrane compartment markers, and was insensitive to BFA. Furthermore, PATL3 localization was not changed in the exo70e2, PRsec6 or exo84b mutants. These data suggested that EXO70A1, but not other exocyst subunits, was responsible for PATL3 localization, which is independent of its role in secretory/recycling vesicle-tethering/fusion. Both EXO70A1 and PATL3 were shown to bind PI4P and PI(4,5)P2 in vitro. Evidence was obtained that the other four members of the PATL family bound to EXO70A1 as well, and shared a similar localization pattern as PATL3. These findings offered new insights into exocyst subunit-specific function, and provided data and tools for further characterization of PATL family proteins.

Abstract (Browse 68)  |  References  |  Full Text HTML  |  Full Text PDF  |  Cited By       
          Molecular Ecology and Evolution
Stigmatic exudate in the Annonaceae: Pollinator reward, pollen germination medium or extragynoecial compitum?  
Author: Jenny Y. Y. Lau, Chun-Chiu Pang, Lawrence Ramsden and Richard M.K. Saunders
Journal of Integrative Plant Biology 1900 待分类(待分类): 1-14
Published Online: September 6, 2017
DOI: 10.1111/jipb.12598
      
    

Although “dry-type” stigmas are widely regarded as ancestral in angiosperms, the early-divergent family Annonaceae has copious stigmatic exudate. We evaluate three putative functions for this exudate: as a nutritive reward for pollinators; as a pollen germination medium; and as an extragynoecial compitum that enables pollen tube growth between carpels. Stigmatic exudate is fructose dominated (72.2%), but with high levels of glucose and sucrose; the dominance of hexose sugars and the diversity of amino acids observed, including many that are essential for insects, support a nutritive role for pollinators. Sugar concentration in pre-receptive flowers is high (28.2%), falling during the peak period of stigmatic receptivity (17.4%), and then rising again toward the end of the pistillate phase (32.9%). Pollen germination was highest in sugar concentrations <20%. Sugar concentrations during the peak pistillate phase therefore provide optimal osmolarity for pollen hydration and germination; subsequent changes in sugar concentration during anthesis reinforce protogyny (in which carpels mature before stamens), enabling the retention of concentrated exudate into the staminate phase as a pollinator food reward without the possibility of pollen germination. Intercarpellary growth of pollen tubes was confirmed: the exudate therefore also functions as a suprastylar extragynoecial compitum, overcoming the limitations of apocarpy.

Abstract (Browse 51)  |  References  |  Full Text HTML  |  Full Text PDF  |  Cited By       
          Functional Omics and Systems Biology
Genetic dissection of top three leaf traits in rice using progenies from a japonica × indica cross
Author: Changbin Yin, Huihui Li, Zhigang Zhao, Zhiquan Wang, Shijia Liu, Liangming Chen, Xi Liu, Yunlu Tian, Juan Ma, Lidong Xu, Dashuang Zhang, Susong Zhu, Danting Li, Jianmin Wan and Jiankang Wang
Journal of Integrative Plant Biology 1900 待分类(待分类): 1-16
Published Online: September 6, 2017
DOI: 10.1111/jipb.12597
      
    

The size of the top three leaves of rice plants is strongly associated with yield; thus, it is important to consider quantitative traits representing leaf size (e.g., length and width) when breeding novel rice varieties. It is challenging to measure such traits on a large scale in the field, and little is known about the genetic factors that determine the size of the top three leaves. In the present study, a population of recombinant inbred lines (RILs) and reciprocal single chromosomal segment substitution lines (SSSLs) derived from the progeny of a japonica Asominori × indica IR24 cross were grown under four diverse environmental conditions. Six morphological traits associated with leaf size were measured, namely length and flag leaf, length and flag, second and third leaves. In the RIL population, 49 QTLs were identified that clustered in 30 genomic region. Twenty-three of these QTLs were confirmed in the SSSL population. A comparison with previously reported genes/QTLs revealed eight novel genomic regions that contained uncharacterized ORFs associated with leaf size. The QTLs identified in this study can be used for marker-assisted breeding and for fine mapping of novel genetic elements controlling leaf size in rice.

Abstract (Browse 74)  |  References  |  Full Text HTML  |  Full Text PDF  |  Cited By       
 

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