Effects of Exogenous ABA and 6-BA on Flag Leaf Senescence in Different Types of Stay-Green Wheat and Relevant Physiological Mechanisms

SUMMARYDelayed senescence, or stay-green, contributes to a longer grain-filling period and has been regarded as a desirable characteristic for the production of a number of crops including wheat. In the present study, in order to identify quantitative trait loci (QTLs) for traits related to the progression of wheat flag leaf senescence, green leaf area duration (GLAD) of a doubled haploid (DH) population, derived from two winter wheat varieties Hanxuan10 and Lumai14, was visually estimated under two water conditions and was recorded at 3-day intervals from 10 days after anthesis to physiological maturity using a 0–9 scale. According to GLAD, parameters related to the progression of senescence of DH lines and their parents were estimated by the Gompertz statistical model. Based on the model parameters, DH lines were categorized into three groups under drought stress and four groups under well-watered conditions. A total of 24 additive QTLs and 23 pairs of epistatic QTLs for parameters related to the progression of senescence were identified on 18 chromosomes, except for 3B, 1D and 6D. Of the QTLs detected, 14 and 10 additive QTLs were associated with the investigated traits under drought stress and well-watered conditions, respectively. Furthermore, 4, 7, 6, 2 and 2 additive QTLs for traits related to progression of senescence were clustered around the same or similar regions of chromosomes 1A, 1B, 5A, 5B and 7A, respectively. The present data provided the genetic basis for high phenotypic correlations among traits related to the progression of wheat flag leaf senescence. In addition, 17 loci were co-located or linked with previously reported QTLs regulating chlorophyll fluorescence, high-light-induced photo-oxidation, or heat stress and dark-induced senescence. The marker Xwmc336 on chromosome 1A, responsible for the onset and end times of leaf senescence, the time to maximum rate of senescence, the time to reach 75% senescence and chlorophyll content under drought stress may be helpful for marker-assisted selection breeding of wheat.

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The involvement of cytokinin and nitrogen metabolism in delayed flag leaf senescence in a wheat stay-green mutant, tasg1

Plant Science ◽

10.1016/j.plantsci.2018.10.024 ◽

2019 ◽

Vol 278 ◽

pp. 70-79 ◽

Cited By ~ 10

Author(s):

Wenqiang Wang ◽

Qunqun Hao ◽

Wenlong Wang ◽

Qinxue Li ◽

Fengjuan Chen ◽

...

Keyword(s):

Nitrogen Metabolism ◽

Leaf Senescence ◽

Flag Leaf ◽

Stay Green ◽

Green Mutant

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Effect of high temperature on leaf senescence and related enzymes of grain starch synthesis in stay-green wheat after anthesis

Chinese Journal of Plant Ecology ◽

10.3724/sp.j.1258.2011.00769 ◽

2011 ◽

Vol 35 (7) ◽

pp. 769-778 ◽

Cited By ~ 2

Author(s):

Hui-Qing SHI ◽

Yue-Hua GONG ◽

Dong-Wu ZHANG

Keyword(s):

High Temperature ◽

Leaf Senescence ◽

Starch Synthesis ◽

Stay Green ◽

Grain Starch

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Genome-wide identification and characterization of long non-coding RNAs involved in flag leaf senescence of rice

Plant Molecular Biology ◽

10.1007/s11103-021-01121-3 ◽

2021 ◽

Author(s):

Xiaoping Huang ◽

Hongyu Zhang ◽

Qiang Wang ◽

Rong Guo ◽

Lingxia Wei ◽

...

Keyword(s):

Transcription Factors ◽

Leaf Senescence ◽

Flag Leaf ◽

Reduction Process ◽

Sequencing Analysis ◽

Biological Processes ◽

Genome Wide ◽

A Genome ◽

Non Coding Rnas ◽

Systematic Identification

Abstract Key message This study showed the systematic identification of long non-coding RNAs (lncRNAs) involving in flag leaf senescence of rice, providing the possible lncRNA-mRNA regulatory relationships and lncRNA-miRNA-mRNA ceRNA networks during leaf senescence. Abstract LncRNAs have been reported to play crucial roles in diverse biological processes. However, no systematic identification of lncRNAs associated with leaf senescence in plants has been studied. In this study, a genome-wide high throughput sequencing analysis was performed using rice flag leaves developing from normal to senescence. A total of 3953 lncRNAs and 38757 mRNAs were identified, of which 343 lncRNAs and 9412 mRNAs were differentially expressed. Through weighted gene co-expression network analysis (WGCNA), 22 continuously down-expressed lncRNAs targeting 812 co-expressed mRNAs and 48 continuously up-expressed lncRNAs targeting 1209 co-expressed mRNAs were considered to be significantly associated with flag leaf senescence. Gene Ontology results suggested that the senescence-associated lncRNAs targeted mRNAs involving in many biological processes, including transcription, hormone response, oxidation–reduction process and substance metabolism. Additionally, 43 senescence-associated lncRNAs were predicted to target 111 co-expressed transcription factors. Interestingly, 8 down-expressed lncRNAs and 29 up-expressed lncRNAs were found to separately target 12 and 20 well-studied senescence-associated genes (SAGs). Furthermore, analysis on the competing endogenous RNA (CeRNA) network revealed that 6 down-expressed lncRNAs possibly regulated 51 co-expressed mRNAs through 15 miRNAs, and 14 up-expressed lncRNAs possibly regulated 117 co-expressed mRNAs through 21 miRNAs. Importantly, by expression validation, a conserved miR164-NAC regulatory pathway was found to be possibly involved in leaf senescence, where lncRNA MSTRG.62092.1 may serve as a ceRNA binding with miR164a and miR164e to regulate three transcription factors. And two key lncRNAs MSTRG.31014.21 and MSTRG.31014.36 also could regulate the abscisic-acid biosynthetic gene BGIOSGA025169 (OsNCED4) and BGIOSGA016313 (NAC family) through osa-miR5809. The possible regulation networks of lncRNAs involving in leaf senescence were discussed, and several candidate lncRNAs were recommended for prior transgenic analysis. These findings will extend the understanding on the regulatory roles of lncRNAs in leaf senescence, and lay a foundation for functional research on candidate lncRNAs.

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Identification of Arabidopsis stay-green mutants with a functional ethylene-response pathway

NZGA: Research and Practice Series ◽

10.33584/rps.14.2008.3176 ◽

2010 ◽

Vol 14 ◽

pp. 119-129

Author(s):

R. Shirzadian-Khorramabad ◽

H.C. Jing ◽

J. Hille ◽

P.P. Dijkwel

Keyword(s):

Shelf Life ◽

Leaf Senescence ◽

Plant Hormone ◽

Floral Induction ◽

Growth Conditions ◽

Pleiotropic Effects ◽

Wild Type ◽

Stay Green ◽

Ethylene Response ◽

Determinant Factor

Natural or harvest-induced senescence is a major determinant factor causing crop losses. The plant hormone ethylene is a strong inducer of senescence and decreasing the ethylene response can reduce senescence, albeit often with undesirable pleiotropic effects. We took advantage of ethylene-induced leaf senescence as a tool to screen for late senescence Arabidopsis mutants that still have a functional ethylenesignalling pathway. Sixteen Arabidopsis onset of leaf death (old) mutants were selected that stayed green after treatment with ethylene. While all the mutants responded to ethylene in a triple response assay, ten mutants responded to the treatment in the same way as the wild type. These ten mutants showed limited pleiotropic effects when grown under standard growth conditions but nine mutants flowered slightly later than the wild type. Genetic characterisation of a subset of the mutants identified several independent loci controlling the leaf senescence process. The approach resulted in the isolation of several stay-green mutants with a functional ethylene response pathway. The late senescence mutants show extended leaf longevity and further research may advance the field of pre- or post-harvest senescence technology. The results, moreover, suggest that there is a correlation between senescence and floral induction. Keywords: Senescence, Arabidopsis, ethylene, mutant, shelf life

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Characterisation of grain yield and nitrogen level in relation to flag leaf senescence of wheat varieties

Physiologia Plantarum ◽

10.1111/j.1399-3054.1986.tb05958.x ◽

1986 ◽

Vol 66 (3) ◽

pp. 503-508 ◽

Cited By ~ 8

Author(s):

I. Ma. Martin del Molino ◽

M. Ulloa ◽

R. Martinez-Carrasco ◽

P. Perez

Keyword(s):

Grain Yield ◽

Leaf Senescence ◽

Flag Leaf ◽

Nitrogen Level ◽

Wheat Varieties

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Leaf Senescence in a Stay-Green Rice Variety, SNU-SG1 and a Mutant, sgr

Photosynthesis. Energy from the Sun ◽

10.1007/978-1-4020-6709-9_325 ◽

2008 ◽

pp. 1515-1518

Author(s):

Min-Hyuk Oh ◽

Tae-Shik Park ◽

Woon-Ho Yang ◽

Kang-Su Kwak ◽

Jin-Chul Shin ◽

...

Keyword(s):

Leaf Senescence ◽

Rice Variety ◽

Stay Green

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Genome-wide H3K9 Acetylation Level Increases with Age-Dependent Senescence of Flag Leaf in Rice (Oryza sativa)

10.1101/2021.11.14.468555 ◽

2021 ◽

Author(s):

Yu Zhang ◽

Yanyun Li ◽

Yuanyuan Zhang ◽

Zeyu Zhang ◽

Deyu Zhang ◽

...

Keyword(s):

Gene Expression ◽

Oryza Sativa ◽

Leaf Senescence ◽

Epigenetic Modification ◽

Flag Leaf ◽

Regulation Of Gene Expression ◽

Leaf Aging ◽

Genome Wide ◽

Age Dependent ◽

H3k9 Acetylation

Flag leaf senescence is an important biological process that drives the remobilization of nutrients to the growing organs of rice. Leaf senescence is controlled by genetic information via gene expression and epigenetic modification, but the precise mechanism is as of yet unclear. Here, we analyzed genome-wide acetylated lysine residue 9 of histone H3 (H3K9ac) enrichment by chromatin immunoprecipitation-sequencing (ChIP-seq) and examined its association with transcriptomes by RNA-seq during flag leaf aging in rice (Oryza sativa). We found that genome-wide H3K9 acetylation levels increased with age-dependent senescence in rice flag leaf, and there was a positive correlation between the density and breadth of H3K9ac and gene expression and transcript elongation. A set of 1,249 up-regulated, differentially expressed genes (DEGs) and 996 down-regulated DEGs showing a strong relationship between temporal changes in gene expression and gain/loss of H3K9ac was observed during rice flag leaf aging. We produced a landscape of H3K9 acetylation- modified gene expression targets that includes known senescence-associated genes, metabolism-related genes, as well as miRNA biosynthesis- related genes. Our findings reveal a complex regulatory network of metabolism- and senescence-related pathways mediated by H3K9ac and also elucidate patterns of H3K9ac-mediated regulation of gene expression during flag leaf aging in rice.

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Genetics and Genomic basis of Stay-green Trait

International Journal of Agriculture Environment and Biotechnology ◽

10.30954/0974-1712.02.2021.1 ◽

2021 ◽

Vol 14 (2) ◽

Author(s):

Harshavardan J Hilli

Keyword(s):

Transcription Factors ◽

Leaf Senescence ◽

Genetic Improvement ◽

Physiological Role ◽

Dimensional Approach ◽

Stay Green ◽

Chlorophyll Pigment ◽

Yield Gain ◽

Genomic Basis ◽

Potential Use

Staygreen is one such trait in which genotypes possessing this trait maintain more photo synthetically active leaves (& less senescent) than genotypes not possessing this trait. Delay of leaf senescence also known as stay-green character, has been identified as an important component in the genetic improvement of several crops to promote stress tolerance and yield gain. Although the stay-green phenotype is superficially similar in all species and genotypes, the genetic and physiological routes the traits are diverse. Photosynthetically active leaves for longer period depends on the concentration of chlorophyll pigment absorbing sunlight for photosynthesis. An multi dimensional approach for studying the senescence pathway rather than studying only the physiological role made a significant role in improvement. Hence new approaches like genomics, proteomics and metabolomics studies are necessary to understand the various transcription factors involved in regulating the leaf senescence process. Therefore, this review has aimed to bring light to major aspects of the stay-green character, showing its potential use in plant breeding.

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