Key Laboratory of Crop Growth Regulation, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, Jiangsu Province, PR China.
J Plant Physiol. 2012 Mar 1;169(4):399-409. doi: 10.1016/j.jplph.2011.09.014. Epub 2012 Jan 12.
Low temperature stress is one of the major abiotic stresses limiting the formation of cotton (Gossypium hirsutum L.) fiber qualities, especially fiber length. To investigate the molecular adaptation mechanisms of cotton fiber elongation to low temperature stress, two cotton cultivars, Kemian 1 (low temperature-tolerant) and Sumian 15 (low temperature-sensitive), were planted in the field at two sowing dates (25 April and 10 June). The two sowing dates resulted in different growing conditions and the main environmental difference between them was temperature, particularly the mean daily minimum temperature (MDTmin). When the sowing date was delayed, the MDTmin decreased from 26.9°C (25 April) to 20.6°C (10 June). Low temperature stress (MDTmin of 20.6°C) shortened the fiber length significantly in two cultivars, but the decreased extent was larger in Sumian 15 than that in Kemian 1. Proteomic analysis of three developmental stages (10, 15 and 20 days post-anthesis [DPA]) showed that 37 spots changed significantly (p<0.05) in abundance under low temperature stress and they were identified using mass spectrometry. These proteins were involved in malate metabolism, soluble sugar metabolism, cell wall loosening, cellulose synthesis, cytoskeleton, cellular response, and redox homeostasis. The results suggest that the enhancement of osmoticum maintenance, cell wall loosening, cell wall components biosynthesis, and cytoskeleton homeostasis plays important roles in the tolerance of cotton fibers to low temperature stress. Moreover, low levels of PEPCase, expansin, and ethylene signaling proteins may potentially lead to the low temperature sensitivity of Sumian 15 at the proteomic level.
低温胁迫是限制棉花（Gossypium hirsutum L.）纤维品质形成的主要非生物胁迫之一，尤其是纤维长度。为了研究棉花纤维对低温胁迫伸长的分子适应机制，在两个播种日期（4 月 25 日和 6 月 10 日）下将两个棉花品种（Kemian 1[耐低温]和 Sumian 15[耐低温]）种植在田间。这两个播种日期导致了不同的生长条件，它们之间的主要环境差异是温度，特别是日平均最低温度（MDTmin）。当播种日期推迟时，MDTmin 从 26.9°C（4 月 25 日）降至 20.6°C（6 月 10 日）。低温胁迫（MDTmin 为 20.6°C）显著缩短了两个品种的纤维长度，但 Sumian 15 的下降幅度大于 Kemian 1。对三个发育阶段（授粉后 10、15 和 20 天[DPA]）的蛋白质组分析表明，37 个斑点在低温胁迫下丰度显著变化（p<0.05），并通过质谱法进行了鉴定。这些蛋白质参与了苹果酸代谢、可溶性糖代谢、细胞壁疏松、纤维素合成、细胞骨架、细胞反应和氧化还原稳态。结果表明，增强渗透维持、细胞壁疏松、细胞壁成分生物合成和细胞骨架稳态在棉花纤维对低温胁迫的耐受中起着重要作用。此外，PEPCase、扩展蛋白和乙烯信号蛋白水平较低可能导致 Sumian 15 在蛋白质组水平上对低温敏感。
