Capturing and Selecting Senescence Variation in Wheat

Senescence is a highly quantitative trait, but in wheat the genetics underpinning senescence regulation remain relatively unknown. To select senescence variation and ultimately identify novel genetic regulators, accurate characterization of senescence phenotypes is essential. When investigating senescence, phenotyping efforts often focus on, or are limited to, the visual assessment of flag leaves. However, senescence is a whole-plant process, involving remobilization and translocation of resources into the developing grain. Furthermore, the temporal progression of senescence poses challenges regarding trait quantification and description, whereupon the different models and approaches applied result in varying definitions of apparently similar metrics. To gain a holistic understanding of senescence, we phenotyped flag leaf and peduncle senescence progression, alongside grain maturation. Reviewing the literature, we identified techniques commonly applied in quantification of senescence variation and developed simple methods to calculate descriptive and discriminatory metrics. To capture senescence dynamism, we developed the idea of calculating thermal time to different flag leaf senescence scores, for which between-year Spearman’s rank correlations of r ≥ 0.59, P < 4.7 × 10–5 (TT70), identify as an accurate phenotyping method. Following our experience of senescence trait genetic mapping, we recognized the need for singular metrics capable of discriminating senescence variation, identifying thermal time to flag leaf senescence score of 70 (TT70) and mean peduncle senescence (MeanPed) scores as most informative. Moreover, grain maturity assessments confirmed a previous association between our staygreen traits and grain fill extension, illustrating trait functionality. Here we review different senescence phenotyping approaches and share our experiences of phenotyping two independent recombinant inbred line (RIL) populations segregating for staygreen traits. Together, we direct readers toward senescence phenotyping methods we found most effective, encouraging their use when investigating and discriminating senescence variation of differing genetic bases, and aid trait selection and weighting in breeding and research programs alike.

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Capturing and Selecting Senescence Variation in Wheat

10.1101/2020.12.06.413641 ◽

2020 ◽

Author(s):

Elizabeth A. Chapman ◽

Simon Orford ◽

Jacob Lage ◽

Simon Griffiths

Keyword(s):

Genetic Mapping ◽

Leaf Senescence ◽

Quantitative Trait ◽

Flag Leaf ◽

Visual Assessment ◽

Thermal Time ◽

Singular Metrics ◽

Whole Plant ◽

Holistic Understanding ◽

Plant Process

AbstractSenescence is a highly quantitative trait, but in wheat the genetics underpinning senescence regulation remain relatively unknown. To select senescence variation, and ultimately identify novel genetic regulators, accurate characterisation of senescence phenotypes is essential. When investigating senescence, phenotyping efforts often focus on, or are limited to, visual assessment of the flag leaves. However, senescence is a whole plant process, involving remobilisation and translocation of resources into the developing grain. Furthermore, the temporal progression of senescence poses challenges regarding trait quantification and description, whereupon the different models and approaches applied result in varying definitions of apparently similar metrics.To gain a holistic understanding of senescence we phenotyped flag leaf and peduncle senescence progression, alongside grain maturation. Reviewing the literature, we identified techniques commonly applied in quantification of senescence variation and developed simple methods to calculate descriptive and discriminatory metrics. To capture senescence dynamism, we developed the idea of calculating thermal time to different flag leaf senescence scores, for which between year Spearman’s rank correlations of r ≥ 0.59, P < 4.7 × 10−5(TT70), identify as an accurate phenotyping method. Following our experience of senescence trait genetic mapping, we recognised the need for singular metrics capable of discriminating senescence variation, identifying Thermal Time to Flag Leaf Senescence score of 70 (TT70) and Mean Peduncle senescence (MeanPed) scores as most informative. Moreover, grain maturity assessments confirmed a previous association between our staygreen traits and grain fill extension, illustrating trait functionality.Here we review different senescence phenotyping approaches and share our experiences of phenotyping two independent RIL populations segregating for staygreen traits. Together, we direct readers towards senescence phenotyping methods we found most effective, encouraging their use when investigating and discriminating senescence variation of differing genetic bases, and to aid trait selection and weighting in breeding and research programs alike.

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Intercropping and Nitrogen Fertilization Altered the Patterns of Leaf Senescence in Sorghum

International Journal of Agronomy ◽

10.1155/2021/5348859 ◽

2021 ◽

Vol 2021 ◽

pp. 1-14

Author(s):

Peter E. Moi ◽

Onesmus M. Kitonyo ◽

George N. Chemining’wa ◽

Josiah M. Kinama

Keyword(s):

Grain Yield ◽

Leaf Senescence ◽

Flag Leaf ◽

Block Design ◽

Fertilizer N ◽

Sole Crop ◽

Whole Plant ◽

Sorghum Grain ◽

Leaf Greenness ◽

Crop System

Leaf senescence regulates grain yield. However, the modulation of leaf senescence in sorghum under legume-based intercrop systems and nitrogen (N) fertilization is not known. The objective of the study was to investigate the effect of intercropping two sorghum (Gadam and Serena) and cowpea (K80, M66) varieties and sole cropping systems and different fertilizer N rates (0, 40, and 80 kg·N·ha−1) on the time course of postflowering sorghum leaf senescence and understand how senescence modulates grain yield. The experiment was laid out in a randomized complete block design with a split-plot arrangement with three replications. Leaf senescence was assessed from flowering to maturity at (a) whole-plant level by the visual scoring of green leaves and (b) flag leaf scale by measuring leaf greenness with a SPAD 502 chlorophyll meter. A logistic function in SigmaPlot was fitted to estimate four traits of leaf senescence, including minimum and maximum SPAD (SPADmin, SPADmax), time to loss of 50% SPADmax (EC50), and the rate of senescence. Irrespective of the cowpea variety, intercropping reduced sorghum grain yield by 50%. The addition of N increased yield by 27% but no effect was detected between 40 and 80 kg·N ha−1. Intercropping delayed leaf senescence at the whole plant by 0.2 leaves plant−1 day−1 but reduced SPADmax of the flag by 8 SPAD units and rate of senescence by 4 SPAD units day−1 compared with sole crop system. Fertilizer N delayed leaf senescence ( P ≤ 0.05 ) at whole-plant and flag leaf scales. Cropping System × nitrogen modulated senescence at whole-plant and flag leaf scales and sorghum grain yield but marginally influenced other traits. While EC50 did not correlate with grain yield, faster rates of senescence and leaf greenness were associated with high yield under the sole crop system. Overall, N was the main factor in driving sorghum leaf senescence while the intercropping effect on senescence was nonfunctional. Effects of competition in sorghum-legume intercropping and source-sink relationships on the patterns of leaf senescence deserve further investigation.

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Identification and characterization of miRNAs during flag leaf senescence in rice by high-throughput sequencing

Plant Physiology Reports ◽

10.1007/s40502-019-0436-6 ◽

2019 ◽

Vol 24 (1) ◽

pp. 1-14

Author(s):

Jyothish Madambikattil Sasi ◽

Cheeni Vijaya Kumar ◽

Balaji Mani ◽

Ankur R. Bhardwaj ◽

Manu Agarwal ◽

...

Keyword(s):

Leaf Senescence ◽

High Throughput ◽

High Throughput Sequencing ◽

Flag Leaf ◽

Identification And Characterization

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

ACTA AGRONOMICA SINICA ◽

10.3724/sp.j.1006.2013.01096 ◽

2013 ◽

Vol 39 (6) ◽

pp. 1096 ◽

Cited By ~ 1

Author(s):

Dong-Qing YANG ◽

Zhen-Lin WANG ◽

Yan-Ping YIN ◽

Ying-Li NI ◽

Wei-Bing YANG ◽

...

Keyword(s):

Leaf Senescence ◽

Flag Leaf ◽

Physiological Mechanisms ◽

Stay Green ◽

Exogenous Aba ◽

Different Types

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Chemical Constituents and Antibacterial Activity of Cissus Aralioides.

Letters in Organic Chemistry ◽

10.2174/1570178617999200609130127 ◽

2020 ◽

Vol 17 ◽

Author(s):

Balogun Olaoye Solomon ◽

Ajayi Olukayode Solomon ◽

Owolabi Temitayo Abidemi ◽

Oladimeji Abdulkarbir Oladele ◽

Liu Zhiqiang

Keyword(s):

Plant Extract ◽

Chemical Constituents ◽

Ethyl Acetate Fraction ◽

Antibacterial Activities ◽

Sub Saharan Africa ◽

Chromatographic Purification ◽

Whole Plant ◽

Sub Saharan ◽

First Time

: Cissus aralioides is a medicinal plant used in sub-Saharan Africa for treatment of infectious diseases; however the chemical constituents of the plant have not been investigated. Thus, in this study, attempt was made at identifying predominant phytochemical constituents of the plant through chromatographic purification and silylation of the plant extract, and subsequent characterization using spectroscopic and GC-MS techniques. The minimum inhibitory concentration (MICs) for the antibacterial activities of the plant extract, chromatographic fractions and isolated compounds were also examined. Chromatographic purification of the ethyl acetate fraction from the whole plant afforded three compounds: β-sitosterol (1), stigmasterol (2) and friedelin (3). The phytosterols (1 and 2) were obtained together as a mixture. The GC-MS analysis of silylated extract indicated alcohols, fatty acids and sugars as predominant classes, with composition of 24.62, 36.90 and 26.52% respectively. Results of MICs indicated that friedelin and other chromatographic fractions had values (0.0626-1.0 mg/mL) comparable with the standard antibiotics used. Characterization of natural products from C. aralioides is being reported for the first time in this study.

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First Insight into Nutraceutical Properties of Local Salento Cichorium intybus Varieties: NMR-Based Metabolomic Approach

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18084057 ◽

2021 ◽

Vol 18 (8) ◽

pp. 4057

Author(s):

Chiara Roberta Girelli ◽

Francesca Serio ◽

Rita Accogli ◽

Federica Angilè ◽

Antonella De Donno ◽

...

Keyword(s):

1H Nmr ◽

Cichorium Intybus ◽

Resonance Spectroscopy ◽

Metabolic Profiles ◽

Whole Plant ◽

Different Content ◽

Insight Into ◽

Nutraceutical Properties ◽

Metabolomic Approach

Background: Plants of genus Cichorium are known for their therapeutic and nutraceutical properties determined by a wealth of phytochemical substances contained in the whole plant. The aim of this paper was to characterize the metabolic profiles of local Salento chicory (Cichorium intybus L.) varieties (“Bianca”, “Galatina”, “Leccese”, and “Otranto”) in order to describe their metabolites composition together with possible bioactivity and health beneficial properties. Methods: The investigation was performed by 1H-NMR spectroscopy and Multivariate Analysis (MVA), by which the metabolic profiles of the samples were easily obtained and compared. Results: The supervised Partial Least Squares Discriminant Analysis (PLS-DA) analysis showed as “Bianca” and “Galatina” samples grouped together separated by “Leccese” and “Otranto” varieties. A different content of free amino acids and organic acids was observed among the varieties. In particular a high content of cichoric and monocaffeoyl tartaric acid was observed for the “Leccese” variety. The presence of secondary metabolites adds significant interest in the investigation of Cichorium inthybus, as this vegetable may benefit human health when incorporated into the diet. Conclusions: The 1H-NMR (Nuclear Magnetic Resonance Spectroscopy) based characterization of Salento chicory varieties allowed us to determine the potential usefulness and nutraceutical properties of the product, also providing a method to guarantee its authenticity on a molecular scale.

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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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