Phenotyping and metabolome analysis reveal the role of AdoMetDC and Di19 genes in determining acquired tolerance to drought in rice

Abstract

Water‐saving attempts for rice cultivation often reduce yields. Maintaining productivity under drought is possible when rice genotypes are bred with improved metabolism and spikelet fertility. Although attempts have been made to introgress water mining and water use efficiency traits, combining acquired tolerance traits (ATTs), that is, specific traits induced or upregulated to better tolerate severe stress, appears equally important. In our study, we screened 90 rice germplasm accessions that represented the molecular and phenotypic variations of 851 lines of the 3 K rice panel. Utilising phenomics, we identified markers linked to ATTs through association analysis of over 0.2 million SNPs derived from whole‐genome sequences. Propensity to respond to ‘induction’ stress varied significantly among genotypes, reflecting differences in cellular protection against oxidative stress. Among the ATTs, the hydroxyl radical and proline contents exhibited the highest variability. Furthermore, these significant variations in ATTs were strongly correlated with spikelet fertility. The 43 significant markers associated with ATTs were further validated using a different subset of contrasting genotypes. Gene expression studies and metabolomic profiling of two well‐known contrasting genotypes, APO (tolerant) and IR64 (sensitive), identified two ATT genes: AdoMetDC and Di19. Our study highlights the relevance of polyamine biosynthesis in modulating ATTs in rice. Genotypes with superior ATTs and the associated markers can be effectively employed in breeding rice varieties with sustained spikelet fertility and grain yield under drought.

Identification and expression of the Di19 gene family in response to abiotic stress in common bean (Phaseolus vulgaris L.)

“…Arabidopsis Z mDi19-1- overexpressing lines exhibit enhanced tolerance to salt stress ( Zhang et al, 2019 ). Furthermore, phenotypic and metabolomic analyses have revealed the role of Di19 in determining acquired drought tolerance in rice ( Sankarapillai et al, 2023 ). A recent study concerning the function of wheat Di19 in plant growth and development indicated that TaDi19-7 overexpression in Arabidopsis significantly promotes flowering and branching in transgenic plants ( Du et al, 2023 ).…”