两种小麦品种绵农4号(Triticum aestivum L. cv. Miannong No.4) 和绵农5号(Triticum aestivum L. cv. Miannong No.5)在渐进水分胁迫下相对含水量、质膜相对透性及光系统ⅡDCIP(2,6-二氯酚靛酚)光化学还原活性变化的差异显示,绵农5号小麦比绵农4号小麦具有较高的水分胁迫耐受力.进而对比了水分胁迫对这两种耐旱性不同的小麦品种的光系统Ⅱ在基因转录及蛋白代谢等方面的影响.结果表明:渐进水分胁迫下,两种小麦的光系统Ⅱ主要基因(psbA、psbD 、cab)的转录本水平及其编码蛋白(D1, D2 、LHCⅡ)的稳态含量分别下降20%及14%以上,而绵农5号cab基因的转录水平下降程度(39.5%)与绵农4号(61.8%)相比明显缓慢,这可能是其具有较高耐旱性的一个重要原因.%Two wheat cultivars, Miannong 4(Triticum aestivum L.cv. Miannong No.4 ) and Miannong 5(Triticum aestivum L. cv. Miannong No.5) were used to study relative water content , relative plasmmembrane permeability , DCIP(2,6-dichlorophenol indophenol) photo redution activities in photosystem Ⅱ under progressive stresses. The differences in these regards showed that Miannong 4 and Miannong 5 had relatively high tolerance to the water stresses. Furthermore, the effects of the water stresses on the gene transcript and protein metabolism of photosystem Ⅱ in the two wheat varieties with different tolerances to the water stresses were also studied. The results showed that under the progressive stresses , the transcripts of major genes(psbA, psbD and cab) and coding proteins (D1,D2, LHCⅡ) of photosystemⅡ decreased by more than 20% and more than 14%, respectively. These reductions became weakened compared with cab transcripts of Miannong 4 and Miannong 5, which was an important reason for relatively high tolerance to water stress.
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