外源烯效唑对干旱胁迫下马铃薯叶片抗氧化能力及渗透调节的影响

Effect of Exogenous Uniconazole on Antioxidant Capacity and Osmotic Adjustment of Potato Leaves under Drought Stress

为探讨外源烯效唑(Uniconazole)对干旱胁迫下马铃薯(Solanum tuberosum)叶片生理参数的影响,2022年在黑龙江省农业科学院克山分院盆栽场进行盆栽试验,以干旱敏感品种大西洋为试验材料,在块茎膨大期(第二花序开花)进行烯效唑和干旱处理,分别设正常水分管理(CK)、正常水分管理+喷施烯效唑(CK+S)、干旱胁迫(D)和干旱胁迫+喷施烯效唑(D+S)4个处理,于喷施烯效唑后第15天进行取样,通过相关性分析、主成分分析等方法研究外源烯效唑对干旱胁迫下马铃薯叶片生长、活性氧积累、抗氧化酶活性、抗坏血酸-谷胱甘肽(ASA-GSH)循环以及渗透调节物质含量的影响。结果表明,外源烯效唑能够明显改善马铃薯叶片的生长状态,D+S处理的叶片叶绿素a(Chl a)和总叶绿素(Chl a+b)含量较D处理显著提高了16.52%和13.85%。喷施烯效唑降低了叶片丙二醛(MDA)、超氧阴离子(O_(2)^(-))产生速率和过氧化氢(H_(2)O_(2))含量,同时提高了抗氧化酶活性以及ASA-GSH循环中的抗坏血酸(ASA)、脱氢抗坏血酸(DHA)、谷胱甘肽(GSH)、氧化型谷胱甘肽(GSSG)含量,起到了清除过量积累的活性氧(ROS)及降低膜脂过氧化程度的作用。另外,外源烯效唑显著提高了干旱胁迫下叶片中可溶性蛋白和脯氨酸含量,减缓了干旱胁迫对叶片生长的抑制作用。外源烯效唑能够促进马铃薯叶片内抗氧化酶、ASA-GSH循环和渗透调节之间的协同作用,从而提高叶片内部还原力水平和抗氧化能力,减轻活性氧对细胞膜造成的损害,提高马铃薯耐旱性。本研究结果为马铃薯抗旱栽培及烯效唑的应用提供了科学依据。

To study the effect of exogenous Uniconazole on physiological parameters of potato leaves under drought stress,a pot experiment was carried out in the potting field of Keshan Branch of Heilongjiang Academy of Agricultural Sciences in 2022 using drought-sensitive variety Atlantic as the experimental material.Uniconazole and drought treatments were carried out during the tuber expansion period(the second inflorescence flowering).Four treatments were set up as follows:normal water management(CK),normal water management+Uniconazole spraying(CK+S),drought stress(D)and drought stress+Uniconazole spraying(D+S).Samples were collected after 15 days of Uniconazole spraying.The effect of exogenous Uniconazole on the growth,active oxygen accumulation,antioxidant enzyme activity,ascorbate-glutathione(ASA-GSH)cycle and osmotic adjustment substance content of potato leaves under drought stress were analyzed by correlation analysis and principal component analysis.Results showed that exogenous Uniconazole could significantly improve the growth of potato leaves.Compared with D treatment,the contents of chlorophyll a(Chl a)and total chlorophyll(Chl a+b)in leaves treated with D+S increased significantly by 16.52%and 13.85%,respectively.Uniconazole spraying reduced MDA,O_(2^(-))production rate and H_(2)O_(2)content in leaves,but increased antioxidant enzyme activity and ASA,GSH,DHA and GSSG content in ASA-GSH cycle,result in a removal of excessive accumulation of ROS and reduced membrane lipid peroxidation.In addition,exogenous Uniconazole could significantly increase the content of soluble protein and proline in leaves,and also alleviate the inhibitory effect of drought stress on leaf growth.Furthermore,exogenous Uniconazole can promote the synergistic effect between antioxidant enzymes,ASA-GSH cycle and osmotic regulation in potato leaves,thereby improving the level of reducing power and antioxidant capacity in leaves,reducing the damage caused by reactive oxygen species to cell membranes,and improving potato drought tolerance.This study provides more scientific basis for drought-resistant cultivation of potato and application of Uniconazole.