Department of Plant Breeding, IFZ Research Centre for Biosystems, Land Use and Nutrition, Justus Liebig University, 35392, Giessen, Germany.
J Integr Plant Biol. 2014 Aug;56(8):797-809. doi: 10.1111/jipb.12199. Epub 2014 May 9.
The impact of osmotic stress on growth, physiology, and metabolism of winter oilseed rape (Brassica napus L.) was investigated by detailed analysis of biomass traits, hormone metabolites and osmolytes in two genetically unrelated drought-tolerant genotypes and two unrelated drought-sensitive genotypes. Seedlings were grown in vitro under controlled conditions and osmotic stress was simulated by applying a gradual treatment with polyethylene glycol (PEG 6000), followed by hypo-osmotic treatment of variants used for metabolite determination. The results provide a basis for the identification of reliable selection criteria for drought resistance in oilseed rape. The in vitro cultivation system established during this study enabled effective discrimination of early osmotic stress responses between drought-resistant and -susceptible oilseed rape genotypes that also show large differences in relative seed yield under drought conditions in the field. Clear physiological and metabolic differences were observed between the drought-resistant and drought-sensitive genotypes, suggesting that osmotic adjustment is a key component of drought response in oilseed rape. Unexpectedly, however, the drought-resistant genotypes did not show typical hormonal adjustment and osmolyte accumulation, suggesting that they possess alternative physiological mechanisms enabling avoidance of stress symptoms.
通过详细分析生物量特征、激素代谢物和渗透物，研究了渗透胁迫对冬油菜（甘蓝型油菜）生长、生理和代谢的影响。在受控条件下体外培养幼苗，并通过逐渐用聚乙二醇（PEG 6000）处理来模拟渗透胁迫，然后对用于代谢物测定的变体进行低渗处理。研究结果为油菜抗旱性的可靠选择标准提供了依据。本研究中建立的体外培养系统能够有效区分抗旱性和敏感性油菜基因型对早期渗透胁迫的反应，这些基因型在田间干旱条件下的相对种子产量也存在很大差异。在抗旱性和敏感性基因型之间观察到明显的生理和代谢差异，表明渗透调节是油菜抗旱反应的一个关键组成部分。然而，出乎意料的是，抗旱性基因型并没有表现出典型的激素调节和渗透物积累，这表明它们具有替代的生理机制，可以避免应激症状。
