Transcriptome analysis of senescence in the flag leaf of wheat (<i>Triticum aestivum</i> L.)

Gregersen, Per L.; Holm, Preben Bach

doi:10.1111/j.1467-7652.2006.00232.x

Cited by 205 publications

(189 citation statements)

References 40 publications

(65 reference statements)

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“…These results suggest that the GPC genes are early regulators of senescence and that senescence is an active process that involves the precise regulation of hundreds of genes. Similar results have been observed in previous transcriptome analyses in other plant species in which senescence-associated gene networks have been shown to be regulated by numerous transcription factors, particularly members of the NAC and WRKY families (Miao et al 2004;Gregersen and Holm 2007;Jukanti et al 2008;Breeze et al 2011).…”

Section: Introductionsupporting

confidence: 77%

Functional characterization of GPC-1 genes in hexaploid wheat

Avni

Zhao

Pearce

et al. 2013

Planta

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In wheat, monocarpic senescence is a tightly regulated process during which nitrogen (N) and micronutrients stored pre-anthesis are remobilized from vegetative tissues to the developing grains. Recently, a close connection between senescence and remobilization was shown through the map-based cloning of the GPC (Grain Protein Content) gene in wheat. GPC-B1 encodes a NAC transcription factor associated with earlier senescence and increased grain protein, iron and zinc content, and is deleted or non-functional in most commercial wheat varieties. In the current research, we identified 'loss of function' ethyl methane sulphonate mutants for the two GPC-B1 homoeologous genes; GPC-A1 and GPC-D1, in a hexaploid wheat mutant population. The single gpc-a1 and gpc-d1 mutants, the double gpc-1 mutant and control lines were grown under field conditions at four locations and were characterized for senescence, GPC, micronutrients and yield parameters. Our results show a significant delay in senescence in both the gpc-a1 and gpc-d1 single mutants and an even stronger effect in the gpc-1 double mutant in all the environments tested in this study. The accumulation of total N in the developing grains showed a similar increase in the control and gpc-1 plants until 25 days after anthesis (DAA) but at 41 and 60 DAA the control plants had higher Grain N content than the gpc-1 mutants. At maturity, GPC in all mutants was significantly lower than in control plants while grain weight was unaffected. These results demonstrate that theGPC-A1 and GPC-D1 genes have a redundant function and play a major role in the regulation of monocarpic senescence and nutrient remobilization in wheat.

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Section: Introductionsupporting

confidence: 77%

Functional characterization of GPC-1 genes in hexaploid wheat

Avni

Zhao

Pearce

et al. 2013

Planta

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“…Rice OsNAC5 was found to be induced earlier and to a greater extent in flag leaves and panicles of rice cultivars with higher seed protein content, indicating that OsNAC5 may be involved in amino acid remobilization from green tissues to seeds [12]. Although there have been some microarray-based transcriptomic studies of senescence in Arabidopsis [13][14][15], Populus [16], wheat [17], and barley [18], little is known about processes that are regulated directly by NAC TFs. Recently, the effect of downregulation of TtNAM-B1 on wheat flag-leaf gene expression during senescence (12 days after anthesis) was investigated using RNA-seq technology [19].…”

Section: Introductionmentioning

confidence: 99%

PvNAC1 and PvNAC2 Are Associated with Leaf Senescence and Nitrogen Use Efficiency in Switchgrass

et al. 2014

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Two full-length cDNAs encoding NAM, ATAF, and CUC (NAC)-family transcription factors (TFs) were isolated from two different cultivars of Panicum virgatum L. (switchgrass) and named PvNAC1 and PvNAC2. Phylogenetic analysis of PvNAC1 and PvNAC2 grouped them with NAC proteins involved in senescence in annual plant species. Transcript profiling revealed that both PvNAC1 and PvNAC2 are induced during leaf senescence. Expression of a PvNAC1-green fluorescent protein (GFP) fusion in plant cells revealed a nuclear location of the protein, consistent with a role in transcriptional regulation. Expression of PvNAC1 in an Arabidopsis nap stay-green mutant suppressed its senescence defect. Expression of PvNAC1 in wild-type Arabidopsis triggered early leaf senescence and remobilization. Transcriptome analysis implicated leaf protein degradation and nitrogen recycling enzymes in NAC-dependent seed protein increase in Arabidopsis. Overexpression of pvNAC2 in switchgrass resulted in increased aboveground biomass associated with increased transcript levels of key nitrogen metabolism genes in leaves and nitrate and ammonium transporter genes in roots. The results indicate that NAC TFs play conserved roles in leaf senescence in the plant kingdom not only in annual monocots and dicots but also in perennial plants such as switchgrass. PvNAC1 and PvNAC2 hold promise for improving nutrient use efficiency in switchgrass through genetic manipulation.

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“…In wheat and barley, the speciic NAC and WRKY transcription factors, in combination with hormones (abscisic acid and jasmonic acid), have been shown to be involved in the regulation of transition between early grain illing and developmental senescence [79,82,83]. Zhao et al [84] identiied a novel NAC1-type transcription factor, TaNAC-S, in wheat, with gene expression located primarily in the leaf/sheath tissues.…”

Section: Genes Involved In Micronutrient Accumulationmentioning

confidence: 99%

Progress and Challenges in Improving Nutritional Quality in Wheat

Lephuthing¹,

Baloyi²,

Sosibo³

et al. 2017

Wheat Improvement, Management and Utilization

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Wheat (Triticum aestivum L.) houses a wide range of nutritional components such as iron (Fe), zinc (Zn), vitamins and phenolic acids, which are important for plant metabolism and human health. The bioavailability of these nutritional components is low due to their interaction with other components and low quantity in the endosperm. Biofortiication is a more sustainable approach that could improve the bioavailability of essential nutritional components. Substantial progress has been made to improve nutritional quality through the application of conventional, technological and transgenic approaches. This has led to the discovery, cloning and introgression of the Gpc-B1 gene; the invention of online databases with minimally characterized biosynthetic, metabolic pathways and biological processes of wheat-related species; the establishment of genetic variation in grain Fe and Zn content and the biofortiication of wheat with Zn by the HarvestPlus organization. Nonetheless, the biofortiication of wheat with micronutrients and phenolic acids is still a challenge due to incomplete understanding of the wheat genome, biosynthesis and translocation of selected nutritional components into diferent wheat grain compartments. There is a need to integrate selected omics technologies to obtain a holistic overview and manipulate key biological processes involved in the remobilization and biosynthesis of nutritional components into desired wheat grain compartments.

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Transcriptome analysis of senescence in the flag leaf of wheat (Triticum aestivum L.)

Cited by 205 publications

References 40 publications

Functional characterization of GPC-1 genes in hexaploid wheat

Functional characterization of GPC-1 genes in hexaploid wheat

PvNAC1 and PvNAC2 Are Associated with Leaf Senescence and Nitrogen Use Efficiency in Switchgrass

Progress and Challenges in Improving Nutritional Quality in Wheat

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