Anbazhagan Krithika, Bhatnagar-Mathur Pooja, Sharma Kiran K, Baddam Rekha, Kishor P B Kavi, Vadez Vincent
International Crops Research Institute for the Semiarid Tropics, Patancheru, Greater Hyderabad 502 324, Andhra Pradesh, India.
Department of Genetics, Osmania University, Hyderabad 500 007, Andhra Pradesh, India.
Funct Plant Biol. 2014 Feb;42(1):84-94. doi: 10.1071/FP14115.
Terminal drought causes major yield loss in chickpea, so it is imperative to identify genotypes with best suited adaptive traits to secure yield in terminal drought-prone environments. Here, we evaluated chickpea (At) rd29A:: (At) DREB1A transgenic events (RD2, RD7, RD9 and RD10) and their untransformed C235 genotype for growth, water use and yield under terminal water-stress (WS) and well-watered (WW) conditions. The assessment was made across three lysimetric trials conducted in contained environments in the greenhouse (2009GH and 2010GH) and the field (2010F). Results from the greenhouse trials showed genotypic variation for harvest index (HI), yield, temporal pattern of flowering and seed filling, temporal pattern of water uptake across crop cycle, and transpiration efficiency (TE) under terminal WS conditions. The mechanisms underlying the yield gain in the WS transgenic events under 2009GH trial was related to conserving water for the reproductive stage in RD7, and setting seeds early in RD10. Water conservation also led to a lower percentage of flower and pod abortion in both RD7 and RD10. Similarly, in the 2010GH trial, reduced water extraction during vegetative stage in events RD2, RD7 and RD9 was critical for better seed filling in the pods produced from late flowers in RD2, and reduced percentage of flower and pod abortion in RD2 and RD9. However, in the 2010F trial, the increased seed yield and HI in RD9 compared with C235 came along only with small changes in water uptake and podding pattern, probably not causal. Events RD2 (2010GH), RD7 (2010GH) and RD10 (2009GH) with higher seed yield also had higher TE than C235. The results suggest that DREB1A, a transcription factor involved in the regulation of several genes of abiotic stress response cascade, influenced the pattern of water uptake and flowering across the crop cycle, leading to reduction in the percentage of flower and pod abortion in the glasshouse trials.
终末期干旱导致鹰嘴豆大幅减产，因此，识别具有最适合适应性状的基因型对于在易发生终末期干旱的环境中确保产量至关重要。在此，我们评估了鹰嘴豆（At）rd29A::（At）DREB1A转基因事件（RD2、RD7、RD9和RD10）及其未转化的C235基因型在终末期水分胁迫（WS）和充分供水（WW）条件下的生长、水分利用和产量。评估是在温室（2009GH和2010GH）和田间（2010F）的受控环境中进行的三项渗漏计试验中进行的。温室试验结果表明，在终末期WS条件下，收获指数（HI）、产量、开花和种子灌浆的时间模式、整个作物周期的水分吸收时间模式以及蒸腾效率（TE）存在基因型差异。2009GH试验中WS转基因事件产量增加的潜在机制与RD7中为生殖阶段保存水分以及RD10中早期结籽有关。水分保存还导致RD7和RD10中花和荚果脱落的百分比降低。同样，在2010GH试验中，RD2、RD7和RD9事件在营养阶段减少水分提取对于RD2中晚期花产生的荚果更好地灌浆以及RD2和RD9中花和荚果脱落百分比降低至关重要。然而，在2010F试验中，与C235相比，RD9中种子产量和HI的增加仅伴随着水分吸收和结荚模式的微小变化，可能没有因果关系。种子产量较高的RD2（2010GH）、RD7（2010GH）和RD10（2009GH）事件的TE也高于C235。结果表明，参与非生物胁迫反应级联的几个基因调控的转录因子DREB1A影响了整个作物周期的水分吸收和开花模式，导致温室试验中花和荚果脱落的百分比降低。
