Transcriptional response of rice flag leaves to restricted external phosphorus supply during grain filling in rice cv. IR64

Abstract

Plant phosphorus (P) remobilisation during leaf senescence has fundamental implications for global P cycle fluxes. Hypothesising that genes involved in remobilisation of P from leaves during grain filling would show altered expression in response to P deprivation, we investigated gene expression in rice flag leaves at 8 days after anthesis (DAA) and 16 DAA in plants that received a continuous supply of P in the nutrient solution vs plants where P was omitted from the nutrient solution for 8 consecutive days prior to measurement. The transcriptional response to growth in the absence of P differed between the early stage (8 DAA) and the later stage (16 DAA) of grain filling. At 8 DAA, rice plants maintained production of energy substrates through upregulation of genes involved in photosynthesis. In contrast, at 16 DAA carbon substrates were produced by degradation of structural polysaccharides and over 50% of highly upregulated genes in P-deprived plants were associated with protein degradation and nitrogen/amino acid transport, suggesting withdrawal of P from the nutrient solution led to accelerated senescence. Genes involved in liberating inorganic P from the organic P compounds and vacuolar P transporters displayed differential expression depending on the stage of grain filling stage and timing of P withdrawal.

Comparative transcriptome analysis reveals a rapid response to phosphorus deficiency in a phosphorus-efficient rice genotype

“…Comparative transcriptomics have effectively been used to dissect underlying genetic mechanisms of a trait in rice 28 , 29 . To reveal genetic components that characterizes the response patterns of DJ123, we obtained transcriptome datasets from 48 leaf and 24 root samples across high- and low-P treatments from DJ123 and IR64.…”

“…Here, we aimed to carry out a comparative transcriptomics analysis between DJ123 and IR64 as it provides an wholistic approach for dissecting genotypic differences 28 , 29 . Our goal was to gain insights on the earlier events that potentially lead to low-P tolerance in DJ123.…”

Dehydration-Responsive Element Binding Protein 1C, 1E, and 1G Promote Stress Tolerance to Chilling, Heat, Drought, and Salt in Rice

“…OsGNA1 , encoding a glucosamine-6-phosphate acetyltransferase, and its LOF mutant has a temperature-sensitive defect in root elongation ( Jiang et al, 2005 ). In addition, OsGRX2 encodes glutaredoxin that is involved in detoxification processes ( Jeong et al, 2018 ) and could contribute to stress tolerance. Five other genes are involved in growth and developmental processes.…”

Variety‐specific transcript accumulation during reproductive stage in drought‐stressed rice

“…Among the 21 VS‐DEGs that acted as a hub gene in co‐expression network analysis, we found that the pathogenesis‐related Bet v I family protein has been previously shown to be regulated by salicylic acid signals (Lv et al 2019). Another gene, namely 'COBRA‐like protein 7/OsPCS13', was found to be responsive to phosphorus deprivation in flag leaves post‐anthesis (Jeong et al 2018). Besides, overexpressing OsWRKY08 has already been reported to improve drought tolerance in Arabidopsis by increasing lateral root number and primary root length (Song et al 2009).…”