铬(Cr~(6+))胁迫对不同基因型小麦种子萌发及幼苗抗氧化和渗透调节的影响

为明确小麦种子萌发对Cr~(6+)胁迫响应的品种间差异及其Cr~(6+)耐性差异的生理机制,以耐Cr~(6+)品种扬麦16和Cr~(6+)敏感品种豫麦51为材料,研究了不同浓度的Cr~(6+)(0、10、50、100、150μmol·L~(-1))处理对种子萌发、α-淀粉酶活性、幼苗生长、活性氧水平、抗氧化酶活性和渗透调节物质含量的影响。结果表明,10mol·L~(-1) Cr~(6+)处理下,小麦种子的萌发过程未受到明显影响。随着Cr~(6+)处理浓度的进一步增加,小麦种子发芽势、发芽率、根长逐渐下降,扬麦16受抑制的程度较豫麦51轻;种子α-淀粉酶活性、根系可溶性蛋白和可溶性糖含量呈现先升后降的趋势;根系游离脯氨酸、丙二醛、O_2~和H_2O_2含量逐渐升高。相同浓度Cr~(6+)处理下,扬麦16的种子α-淀粉酶活性、根系可溶性糖和游离脯氨酸含量显著高于豫麦51,而根系丙二醛、O_2~和H_2O_2的含量显著低于豫麦51。在Cr~(6+)胁迫下,小麦根系SOD、POD、APX和GR的活性总体上呈现先升后降的趋势。在高浓度Cr~(6+)(150mol·L~(-1))处理下,扬麦16的种子α-淀粉酶、根系SOD、POD、APX和GR活性受抑制程度均明显小于豫麦51。

Effect of Chromium (Cr6+) Stress on Seed Germination,Anti-oxidation and Osmotic Adjustment in Seedling of Different Genotypes of Wheat

In order to clarify the response to Cr6+ stress of different genotypes of wheat and its tolerance mechanism,Yangmai 16 (Cr6+ tolerance) and Yumai 51 (Cr6+ sensitivity) were used to study the influence of different concentration of Cr6+ (0,10,50,100 and 150μmol · L-1) treatments on seed germination,seedling growth,activities of α-amylase during seed germination,antioxidant enzymes,the level of oxidative stress and osmotic regulator contents change in the seedling roots.The results showed that with the increase of Cr6+ concentration,the germination potential,germination percentage,length of root and shoot of two wheat varieties were gradually inhibited,and the decreases in Yangmai 16 were less than those in Yumai 51;comparing to control treatment,the activity of α-amylase and content of soluble protein and soluble sugar was first increased and then declined;while content of proline,malondialdehyde,O2-· and H2O2 were gradually increased.Under the same concentration of Cr6+ treatment,the activity of α-amylase,and content of soluble sugar and proline of Yangmai 16 were significantly higher than that in Yumai 51,while content of MDA,O2-· and H2O2 of Yangmail6 were significantly lower than that in Yumai 51.Comparing to control treatment,the activity of SOD,POD,APX and GR in the roots of two wheat cultivars were generally increased first and then decreased with the increase of Cr6+ concentration.Furthermore,under 150 μmol · L-1 Cr6+ concentration,the activity of α-amylase,SOD,POD,APX and GR of Yangmai 16 were less inhibited than Yumai 51.