Drought is one of the major constraints in wheat production and causes a huge loss at grain-filling stage. In this study we highlighted the response of different wheat genotypes under drought stress at the grain-filling stage. Field experiments were conducted to evaluate 72 wheat (Triticum aestivum L.) genotypes under two water regimes: irrigated and drought condition. Four wheat genotypes, two each of drought tolerant (IC36761A, IC128335) and drought-susceptible category (IC335732 and IC138852) were selected on the basis of agronomic traits and drought susceptibility index (DSI), to understand their morphological, biochemical and molecular basis of drought stress tolerance. Among agronomic traits, productive tillers followed by biomass had high percent reduction under drought stress, thus drought stress had a great impact. Antioxidant activity (AO), total phenolic and proline content were found to be significantly higher in IC128335 genotype. Differential expression pattern of transcription factors of ten genes revealed that transcription factor qTaWRKY2 followed by qTaDREB, qTaEXPB23 and qTaAPEX might be utilized for developing wheat varieties resistant to drought stress. Understanding the role of TFs would be helpful to decipher the molecular mechanism involved in drought stress. Identified genotypes (IC128335 and IC36761A) may be useful as parental material for future breeding program to generate new drought-tolerant varieties.

干旱是小麦生产的主要制约因素之一，在灌浆期造成巨大损失。在这项研究中，我们强调了不同小麦基因型在灌浆期干旱胁迫下的反应。通过田间试验评估了 72 个小麦 ( Triticum aestivum L.) 基因型在两种水况下的情况：灌溉和干旱条件。根据农艺性状和干旱敏感性指数（DSI）选择了四种小麦基因型，其中耐旱基因型（IC36761A，IC128335）和易旱基因型（IC335732和IC138852）各两个，以了解其形态、生化和分子基础。干旱胁迫耐受性。农艺性状中，干旱胁迫下分蘖率下降幅度较大，生物量次之，干旱胁迫影响较大。IC128335 基因型的抗氧化活性（AO）、总酚和脯氨酸含量显着较高。10个基因转录因子的差异表达模式表明，转录因子qTaWRKY2、qTaDREB、qTaEXPB23和qTaAPEX可能可用于开发抗干旱胁迫的小麦品种。了解转录因子的作用将有助于破译干旱胁迫中涉及的分子机制。已鉴定的基因型（IC128335 和 IC36761A）可用作未来育种计划的亲本材料，以产生新的耐旱品种。