Response of the Flag Leaves of a Super-Hybrid Rice Variety to Drought Stress during Grain Filling Period

We report a case study of natural variations and correlations of some photosynthetic parameters, green biomass and grain yield in Cappelle Desprez and Plainsman V winter wheat (Triticum aestivumL.) cultivars, which are classified as being drought sensitive and tolerant, respectively. We monitored biomass accumulation from secondary leaves in the vegetative phase and grain yield from flag leaves in the grain filling period. Interestingly, we observed higher biomass production, but lower grain yield stability in the sensitive Cappelle cultivar, as compared to the tolerant Plainsman cv. Higher biomass production in the sensitive variety was correlated with enhanced water-use efficiency. Increased cyclic electron flow around PSI was also observed in the Cappelle cv. under drought stress as shown by light intensity dependence of the ratio of maximal quantum yields of Photosystem I and Photosystem II, as well by the plot of the Photosystem I electron transport rate as a function of Photosystem II electron transport rate. Higher CO2uptake rate in flag leaves of the drought-stressed Plainsman cv. during grain filling period correlates well with its higher grain yield and prolonged transpiration rate through spikes. The increase in drought factor (DFI) and performance (PI) indices calculated from variable chlorophyll fluorescence parameters of secondary leaves also showed correlation with higher biomass in the Cappelle cultivar during the biomass accumulation period. However, during the grain filling period, DFI and PI parameters of the flag leaves were higher in the tolerant Plainsman V cultivar and showed correlation with grain yield stability. Our results suggest that overall biomass and grain yield may respond differentially to drought stress in different wheat cultivars and therefore phenotyping for green biomass cannot be used as a general approach to predict grain yield. We also conclude that photosynthetic efficiency of flag and secondary leaves is correlated with grain yield and green biomass, respectively. In addition, secondary trait associated mechanisms like delayed senescence and higher water-use efficiency also contribute to biomass stability. Our studies further prove that photosynthetic parameters could be used to characterize environmental stress responses.

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Unique Transcriptome And Gene Expression Analysis of Flag Leaves of A Super-Hybrid Rice WFYT025

10.21203/rs.3.rs-490906/v1 ◽

2021 ◽

Author(s):

Qin Cheng ◽

Shiying Huang ◽

Peng Wang ◽

Shilei Liu ◽

Guangliang Wu ◽

...

Keyword(s):

Hybrid Rice ◽

Flag Leaf ◽

Grain Filling ◽

Additive Effect ◽

Dominant Effect ◽

Partial Dominance ◽

Flag Leaves ◽

Super Hybrid Rice ◽

Highly Expressed Genes ◽

Two Stages

Abstract Background: The health and physiology of flag leaves are closely related to rice yield, and flag leaves play an important role in providing photosynthetic products during grain filling, many breeding studies have tried to improve the performance of flag leaves. However, there are few studies on the heterosis of rice flag leaves up to now. Results: Thus, the present research is focused on the flag leaves heterosis of a widely used late-cropping indica super hybrid rice combination WFYT025 in China using a high-throughput next-generation RNA-seq strategy under different environment with two stages, trying to find some genes related to photosynthesis, transpiration, and development of seeds. Mid-parent heterosis (MPH) and higher parent heterosis (HPH) were estimated for the heterosis of flag leaf. Under the environment of middle rice, the number of genes up-regulated in CHT025, WFB and WFYT025 were 892,1,273 and 819, down-regulated in CHT025, WFB and WFYT025 were 616,1934 and 2196, respectively. Among the SDGhps on the first day after flowering, 10.9% had a dominant effect, 41.81% had a partial dominant effect, 22.07% had an additive effect and the remaining 25.22% had an over-dominant effect. Meanwhile, on the tenth day after flowering, there were 491 genes, accounting for 27.16%, showed over-dominance; 222 genes, accounting for 12.28%, showed dominance; 760 genes, accounting for 42.04%, showed partial dominance; and 335 genes, accounting for 18.52%, showed additive effect. Conclusion: The co-expressed gene sets via weighted gene co-expression network analysis (WGCNA) were identified, and total of 5,000 highly expressed genes were divided into 24 co-expression groups. In the two stages, we found 9 identical transcription factors. Except for 5 reported TFs, the other 4 TFs may play an important role in grain number and photosynthesis heterosis.

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Effects of Drought Stress on Some Agronomic and Morpho-Physiological Traits in Durum Wheat Genotypes

Sustainability ◽

10.3390/su12145610 ◽

2020 ◽

Vol 12 (14) ◽

pp. 5610

Author(s):

Alireza Pour-Aboughadareh ◽

Reza Mohammadi ◽

Alireza Etminan ◽

Lia Shooshtari ◽

Neda Maleki-Tabrizi ◽

...

Keyword(s):

Drought Stress ◽

Grain Yield ◽

Durum Wheat ◽

Harvest Index ◽

Plant Biomass ◽

Geometric Mean ◽

Grain Filling ◽

Tolerance Index ◽

Wheat Genotypes ◽

Grain Filling Period

Durum wheat performance in the Mediterranean climate is limited when water scarcity occurs before and during anthesis. The present research was performed to determine the effect of drought stress on several physiological and agro-morphological traits in 17 durum wheat genotypes under two conditions (control and drought) over two years. The results of analysis of variance indicated that the various durum wheat genotypes responded differently to drought stress. Drought stress significantly reduced the grain filling period, plant height, peduncle length, number of spikes per plot, number of grains per spike, thousand grains weight, grain yield, biomass, and harvest index in all genotypes compared to the control condition. The heatmap-based correlation analysis indicated that grain yield was positively and significantly associated with phenological characters (days to heading, days to physiological maturity, and grain filling period), as well as number of spikes per plant, biomass, and harvest index under drought conditions. The yield-based drought and susceptible indices revealed that stress tolerance index (STI), geometric mean productivity (GMP), mean productivity (MP), and harmonic mean (HM) were positively and significantly correlated with grain yields in both conditions. Based on the average of the sum of ranks across all indices and a three-dimensional plot, two genotypes (G9 and G12) along with the control variety (G1) were identified as the most tolerant genotypes. Among the investigated genotypes, the new breeding genotype G12 showed a high drought tolerance and yield performance under both conditions. Hence, this genotype can be a candidate for further multi-years and locations test as recommended for cultivation under rainfed conditions in arid and semi-arid regions.

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Dynamics of phytohormones and their relationship with chalkiness of early indica rice under different post-anthesis temperature regimes

Bangladesh Journal of Agricultural Research ◽

10.3329/bjar.v42i1.31975 ◽

2017 ◽

Vol 42 (1) ◽

pp. 53-65

Author(s):

Mohammed Humayun Kabir ◽

Qing Liu ◽

Yi Su ◽

Zhigang Huang ◽

Langtao Xiao

Keyword(s):

High Temperature ◽

Low Temperature ◽

Indica Rice ◽

Grain Filling ◽

Flag Leaves ◽

Content Ratio ◽

Temperature Regimes ◽

Head Rice ◽

Grain Filling Period ◽

Early Indica Rice

A pot experiment on an early indica rice cv. Shenyou9576 was conducted in the net house of Hunan Agricultural University, Changsha, Hunan, PR China during the early growing season of 2013 to investigate the influence of varying temperatures on chalkiness rate, head rice rate, and phytohormones, namely indole-3-acetic acid (IAA), gibberellins (GA1 and GA4), zeatin (Z), zeatin riboside (ZR) and abscisic acid (ABA) both in flag leaves and grain endosperm during grain filling period. The treatments comprised three temperature regimes which are designated as the high (35/28oC- day/night), low (25/20oC- day/night) and natural condition as the control (35/25oC- day/night). The results showed that the maximum chalkiness rate was 61.11% under high temperature and the minimum (22.59%) under low temperature. The lowest head rice rate was 42.76% under high temperature followed by 49.91% in the control, while the highest (62.33%) under low temperature. The contents of GA1, GA4, Z and ZR were decreased gradually from 7 to 35 days after anthesis (DAA) irrespective of treatments. IAA content began to decrease from 14 DAA and continued up to 35 DAA and ABA was reduced from 28 to 35 DAA under low temperature in comparison to control and high temperature. ABA content was increased from 7 to 21 DAA and then declined at high temperature. The results showed that contents of GA1, GA4, Z, ZR were high at low temperature compared to high temperature and control. IAA content was also high during grain development period at low temperature except 7 DAA. Higher phytohormone contents were observed in endosperm than in flag leaves. Phytohormone content ratio (endosperm: flag leaves) was found highest in IAA and the lowest in GA1. A significant positive correlation was found between ABA and chalkiness rate during early to mid grain filling period, while significant negative correlations were noticed between chalkiness rate and other phytohormones during grain filling period. Correlation results revealed that increased level of ABA during early to mid grain filing period caused by high temperature was more responsible for development of chalkiness.Bangladesh J. Agril. Res. 42(1): 53-65, March 2017

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Transcriptome and genome sequencing elucidates the molecular basis for the high yield and good quality of the hybrid rice variety Chuanyou6203

Scientific Reports ◽

10.1038/s41598-020-76762-3 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Juansheng Ren ◽

Fan Zhang ◽

Fangyuan Gao ◽

Lihua Zeng ◽

Xianjun Lu ◽

...

Keyword(s):

Molecular Mechanism ◽

Hybrid Rice ◽

Rice Variety ◽

Utilization Efficiency ◽

High Yield ◽

Mrna Editing ◽

High Quality ◽

Flag Leaves ◽

Yield And Quality

AbstractThe yield heterosis of rice is sought by farmers and strong contributes to food safety, but the quality of hybrid rice may be reduced. Therefore, developing new varieties with both high yield and good quality is a heavily researched topic in hybrid rice breeding. However, the molecular mechanism governing yield heterosis and high rice quality has not been elucidated to date. In this study, a comparative transcriptomics and genomic analysis was performed on a hybrid rice variety, Chuanyou6203 (CY6203), and its parents to investigate the molecular mechanism and gene regulation network governing the formation of yield and quality stages. A total of 66,319 SNPs and InDels between CH3203 and C106B were detected in the 5′-UTR, exon, intronic, and 3′-UTR regions according to the reference genome annotation, which involved 7473 genes. A total of 436, 70, 551, 993, and 1216 common DEGs between CY6203 and both of its parents were identified at the same stage in panicles and flag leaves. Of the common DEGs, the numbers of upregulated DEGs between CY6203 and CH3203 were all greater than those of upregulated DEGs between CY6203 and C106B in panicles and flag leaves at the booting, flowering, and middle filling stages. Approximately 40.61% of mRNA editing ratios were between 0.4 and 0.6, and 1.68% of mRNA editing events (editing ratio ≥ 0.8) in CY6203 favored one of its parents at three stages or a particular stage, suggesting that the hypothetical heterosis mechanism of CY6203 might involve dominance or epistasis. Also 15,934 DEGs were classified into 19 distinct modules that were classified into three groups by the weighted gene coexpression network analysis. Through transcriptome analysis of panicles and flag leaves in the yield and quality stages, the DEGs in the green-yellow module primarily contributed to the increase in the source of CY6203 due to an in increase in photosynthetic efficiency and nitrogen utilization efficiency, and a small number of DEGs related to the grain number added spikelet number per panicle amplified its sink. The balanced expression of the major high-quality alleles of C106B and CH3203 in CY6203 contributed to the outstanding quality of CY6203. Our transcriptome and genome analyses offer a new data set that may help to elucidate the molecular mechanism governing the yield heterosis and high quality of a hybrid rice variety.

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Effects of High Temperature on Antioxidant Enzymes and Lipid Peroxidation in Flag Leaves of Wheat During Grain Filling Period

Agricultural Sciences in China ◽

10.1016/s1671-2927(06)60071-0 ◽

2006 ◽

Vol 5 (6) ◽

pp. 425-430 ◽

Cited By ~ 8

Author(s):

Ping LIU ◽

Wen-shan GUO ◽

Han-chun PU ◽

Chao-nian FENG ◽

Xin-kai ZHU ◽

...

Keyword(s):

Lipid Peroxidation ◽

Antioxidant Enzymes ◽

High Temperature ◽

Grain Filling ◽

Flag Leaves ◽

Grain Filling Period

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The relationship between flag leaf senescence and grain yield of some durum wheat varieties under drought stress during grain filling period

Tarım Bilimleri Dergisi ◽

10.1501/tarimbil_0000001341 ◽

2015 ◽

Vol 21 (3) ◽

pp. 382-393

Author(s):

TİRYAKİOĞLU Murat

Keyword(s):

Drought Stress ◽

Grain Yield ◽

Durum Wheat ◽

Leaf Senescence ◽

Flag Leaf ◽

Grain Filling ◽

Wheat Varieties ◽

Grain Filling Period ◽

The Relationship

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Genes differentially expressed under photoinhibition stress in flag leaves of super-hybrid rice Liangyoupeijiu (Oryza sativa) and their genetic origins

Photosynthetica ◽

10.1007/s11099-005-0038-6 ◽

2005 ◽

Vol 43 (2) ◽

pp. 231-236 ◽

Cited By ~ 3

Author(s):

G. Q. Jiang ◽

J. L. Guo ◽

Q. W. Meng ◽

Y. Q. Chen ◽

H. X. Wang ◽

...

Keyword(s):

Oryza Sativa ◽

Hybrid Rice ◽

Differentially Expressed ◽

Flag Leaves ◽

Super Hybrid Rice ◽

Genetic Origins

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The Role of Fertilizer Management in the Development and Expression of Crop Drought Stress in Cereals under Mediterranean Environmental Conditions

Experimental Agriculture ◽

10.1017/s0014479700012564 ◽

1985 ◽

Vol 21 (3) ◽

pp. 209-222 ◽

Cited By ~ 10

Author(s):

J. D. H. Keatinge ◽

P. J. H. Neate ◽

K. D. Shepherd

Keyword(s):

Drought Stress ◽

Environmental Conditions ◽

Crop Yields ◽

Grain Filling ◽

Fertilizer Management ◽

Fertilizer N ◽

Kernel Weights ◽

Grain Filling Period ◽

Heavy Nitrogen

SUMMARYThe development and influence of crop drought stress was examined in winter-planted small-grain cereals under Mediterranean environmental conditions. In two average or wetter than average years crop drought stress in the grain-filling period was greatly exacerbated by the addition of fertilizer (N and P) and this usually resulted in significantly lower kernel weights. Yet this reduction was not so substantial as to seriously affect crop yields. Total grain yields were largest in treatments receiving fertilizer, due to greater spike numbers and numbers of kernels per spike. But heavy nitrogen applications may promote the risk of a large proportion of small or shrivelled grains in a dry year.

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