NaCl胁迫对小麦抗盐突变体根液泡膜H^+ ATP酶和H^+ PP酶活性的影响

Effects of NaCl Stress on H^+ ATPase and H^+ PPase Activities of Tonoplast enriched Vesicles Isolated from the Roots of Salt tolerant Mutant of Wheat and Its Wild Type

随着盐胁迫强度（ ＮａＣｌ ０ ～１５０ｍ ｍｏｌ／Ｌ） 和时间（０ ～７２ ｈ） 的增加，小麦抗盐突变体根液泡膜Ｈ＋ＡＴＰ 酶和Ｈ＋ＰＰ 酶活性显著增加，虽然野生型酶活性在盐胁迫下也有增加，但其增加的幅度显著低于突变体，Ｈ＋ＰＰ酶活性的差异更为显著。Ｈ＋ＡＴＰ酶和Ｈ＋ＰＰ酶的最适ｐＨ 值在两者之间以及盐胁迫前后均无改变，分别为７ ．０ 和８ ．０ 。无盐胁迫下野生型液胞膜５８ ｋＤ 蛋白带缺失，盐胁迫下这一蛋白有微弱的表达。与此不同，突变体５８ ｋＤ 蛋白在盐胁迫前后均有明显的表达，但其２９ ｋＤ 蛋白带在无盐胁迫下明显减弱。

The activities of H + ATPase and H + PPase increased more significantly in tonoplast isolated from the mutant than that from the wild type when they were treated with NaCl stress at different salt strengths and different stress durations(Figs.1,2). The optimum pHs of H + ATPase and H + PPase were 7.0 and 8.0 respectively in the mutant and wild type when treated with control condition or NaCl 150 mmol/L for 3 days, which indicated that salt stress did not alter the pH profile of these two enzymes. The analyzing results of characterization of tonoplast polypeptides showed that the 58 kD peptide was absent in wild type under control condition and salt stress a small amount of this peptide was found. The mutant had a relatively mire amount of the 58 kD peptide under control condition or salt stress treatment, but its 29 kD peptide disappeared under control condition. We discussed the relationship between the enhancement of H + translocating abilities and the increase of H + ATPase and H + PPase activities in the tonoplast enriched vesicles isolated from roots of the mutant and wild type treated with salt stress.