Suneja Yadhu, Gupta Anil Kumar, Bains Navtej Singh
Department of Biochemistry, Punjab Agricultural University, Ludhiana, India.
Department of Plant Breeding and Genetics, Punjab Agricultural University, Ludhiana, India.
Front Plant Sci. 2019 Feb 25;10:211. doi: 10.3389/fpls.2019.00211. eCollection 2019.
The inconsistent prevalence of abiotic stress in most of the agroecosystems can be addressed through deployment of plant material with stress adaptive plasticity. The present study explores water stress induced plasticity for early root-shoot development, proline induction and cell membrane injury in 57 accessions of (DD-genome) and 26 accessions of (AABB-genome) along with durum and bread wheat cultivars. Thirty three accessions and 18 accessions showed an increase in root dry weight (ranging from 1.8 to 294.75%) under water stress. Shoot parameters- length and biomass, by and large were suppressed by water stress, but genotypes with stress adaptive plasticity leading to improvement of shoot traits (e.g., accession 14191 and accession 7130) could be identified. Water stress induced active responses, rather than passive repartitioning of biomass was indicated by better shoot growth in seedlings of genotypes with enhanced root growth under stress. Membrane injury seemed to work as a trigger to activate water stress adaptive cellular machinery and was found positively correlated with several root-shoot based adaptive responses in seedlings. Stress induced proline accumulation in leaf tissue showed marked inter- and intra-specific genetic variation but hardly any association with stress adaptive plasticity. Genotypic variation for early stage plasticity traits viz., change in root dry weight, shoot length, shoot fresh weight, shoot dry weight and membrane injury positively correlated with grain weight based stress tolerance index ( = 0.267, = 0.404, = 0.299, = 0.526, and = 0.359, respectively). In another such trend, adaptive seedling plasticity correlated positively with resistance to early flowering under stress ( = 0.372 with membrane injury, = 0.286 with change in root length, = 0.352 with change in shoot length, = 0.268 with change in shoot dry weight). Overall, accessions 9816, 14109, 14128, and accessions 5259 and 7130 were identified as potential donors of stress adaptive plasticity. The prospect of the study for molecular marker tagging, cloning of plasticity genes and creation of elite synthetic hexaploid donors is discussed.
大多数农业生态系统中abiotic胁迫发生率不一致的问题，可以通过部署具有胁迫适应性可塑性的植物材料来解决。本研究探讨了水分胁迫诱导的可塑性对57份（DD基因组）和26份（AABB基因组）以及硬粒小麦和面包小麦品种早期根茎发育、脯氨酸诱导和细胞膜损伤的影响。33份和18份在水分胁迫下根干重增加（增幅从1.8%到294.75%）。地上部参数——长度和生物量，总体上受到水分胁迫的抑制，但可以鉴定出具有胁迫适应性可塑性从而改善地上部性状的基因型（例如，品种14191和品种7130）。胁迫下根系生长增强的基因型幼苗地上部生长更好，这表明水分胁迫诱导的是积极响应，而非生物量的被动重新分配。膜损伤似乎是激活水分胁迫适应性细胞机制的触发因素，并且发现其与幼苗中几种基于根茎的适应性反应呈正相关。胁迫诱导的叶片组织脯氨酸积累表现出明显的种间和种内遗传变异，但与胁迫适应性可塑性几乎没有关联。早期可塑性性状的基因型变异，即根干重、地上部长度、地上部鲜重、地上部干重和膜损伤的变化，与基于粒重的胁迫耐受指数呈正相关（分别为 = 0.267， = 0.404， = 0.299， = 0.526，以及 = 0.359）。在另一种这样的趋势中，适应性幼苗可塑性与胁迫下对早花的抗性呈正相关（与膜损伤相关系数为 = 0.372，与根长度变化相关系数为 = 0.286，与地上部长度变化相关系数为 = 0.352，与地上部干重变化相关系数为 = 0.268）。总体而言，品种9816、14109、14128以及品种5259和7130被鉴定为胁迫适应性可塑性的潜在供体。本文还讨论了该研究在分子标记定位、可塑性基因克隆以及创建优良合成六倍体供体方面的前景。
