Sankarapillai Lekshmy V, Vijayaraghavareddy Preethi, Nanaiah Karthik, Arpitha Gajamaranahally D, Chaitanya Purushothama M, Sathishraj Rajendran, Shindhe Dhananjay, Vemanna Ramu S, Yin Xinyou, Struik Paul C, Sreeman Sheshshayee
Department of Crop Physiology, University of Agricultural Sciences, Bengaluru, India.
Centre for Crop Systems Analysis, Department of Plant Sciences, Wageningen University & Research, Wageningen, the Netherlands.
Physiol Plant. 2023 Sep-Oct;175(5):e13992. doi: 10.1111/ppl.13992.
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.
水稻种植的节水尝试往往会降低产量。当培育出具有改善的代谢和小穗育性的水稻基因型时，在干旱条件下维持生产力是可能的。尽管已经尝试导入水分利用和水分利用效率性状，但结合获得性耐受性状（ATTs），即诱导或上调以更好地耐受严重胁迫的特定性状，似乎同样重要。在我们的研究中，我们筛选了90份水稻种质资源，它们代表了3K水稻群体851个品系的分子和表型变异。利用表型组学，我们通过对来自全基因组序列的超过20万个单核苷酸多态性（SNP）进行关联分析，鉴定了与ATTs相关的标记。基因型对“诱导”胁迫的响应倾向差异显著，反映了细胞对氧化胁迫的保护差异。在ATTs中，羟自由基和脯氨酸含量的变异性最高。此外，ATTs的这些显著变异与小穗育性密切相关。使用不同的对比基因型子集进一步验证了与ATTs相关的43个显著标记。对两个著名的对比基因型APO（耐受型）和IR64（敏感型）进行基因表达研究和代谢组分析，鉴定出两个ATT基因：AdoMetDC和Di19。我们的研究强调了多胺生物合成在调节水稻ATTs中的相关性。具有优异ATTs和相关标记的基因型可有效地用于培育在干旱条件下具有持续小穗育性和籽粒产量的水稻品种。
