外源脯氨酸对缓解红砂干旱胁迫的机理研究  

A study of the mechanism of drought stress alleviation by exogenous proline applied to Reaumuria soongorica

作　　者：苏世平[1] 李毅[1] 刘小娥[1] 种培芳[1] 单立山[1] 后有丽 SU Shi-ping;LI Yi;LIU Xiao-e;CHONG Pei-fang;SHAN Li-shan;HOU You-li(College of Forestry,Gansu Agricultural University,Lanzhou 730070,China)

机构地区：[1]甘肃农业大学林学院,甘肃兰州730070

出　　处：《草业学报》2022年第6期127-138,共12页Acta Prataculturae Sinica

基　　金：国家自然科学基金(32060335,41661067);对发展中国家常规性科技援助项目(KY202002011)资助。

摘　　要：红砂属于干旱半干旱荒漠区生态系统中重要的超抗旱树种,对维护荒漠区植物群落的稳定性具有重要的作用。近年来由于极端干旱气候的频发,导致以红砂为建群种的荒漠植物群落出现大面积死亡以及退化的趋势。因此,采用人工措施提高干旱荒漠区植物的抗旱能力显得尤为重要。通过对干旱胁迫中的红砂苗木喷施外源脯氨酸(Pro)以减缓干旱胁迫对其造成的伤害。研究设置5个Pro浓度,分别为50,100,150,200,250 mg·L^(-1),对红砂植株进行喷施处理,于处理前第0天(CK),处理后第1,3,6和9天对叶片抗氧化酶系统、代谢调节系统、光合色素、光合性能进行测定,第9天对生长状况进行测定,以期揭示干旱胁迫下Pro的作用机理。结果表明,外源Pro处理红砂植株后,对其抗氧化酶系统、代谢调节系统、光合色素、光合性能以及生长状况均有显著影响。除叶绿素a/b(Chl a/b)在处理年份间差异不显著,可溶性糖含量在处理浓度间差异不显著外,其他指标在处理年份之间、处理浓度之间、处理后作用时间之间以及处理浓度与处理后作用时间交互作用之间均差异显著,其中以100 mg·L^(-1)Pro处理效果最佳。100 mg·L^(-1)Pro处理后第9天和CK相比,可溶性蛋白(SP)、脯氨酸(Pro)、过氧化氢酶(CAT)、过氧化物酶(POD)分别提高了4.48%、131.07%、30.66%、12.30%,可溶性糖(SS)、超氧化物歧化酶(SOD)分别下降了6.42%、1.95%;总叶绿素含量Chl(a+b)、叶绿素a含量(Chla)、叶绿素b含量(Chlb)分别较CK降低了5.81%、1.47%和22.22%;净光合速率(Pn)、气孔导度(GS)、蒸腾速率(Tr)、胞间二氧化碳浓度(Ci)以及水分利用效率(WUE)分别比CK降低了16.07%、10.00%、6.44%、7.68%和9.92%;红砂苗木的生长特性在处理后第9天,株高净生长量为2.48 cm,侧芽萌发数量为3.67个,侧芽净生长量为1.87 cm,地径净生长量为0.27 mm,比处理效果最差的250 mg·L^(-1)处理分别高出0.68 cm,Reaumuria soongorica is an important and extremely drought-resistant tree species found in arid and semiarid desert ecosystems in the Northwest of China.R.soongorica plays an important role in maintaining the stability of plant communities in semi-desert environments.In recent years,because of frequent occurrence of extreme drought conditions,R.soongorica desert plant communities have sustained large areas of death and are exhibiting degradation.To counter this trend,adoption of artificial measures to improve the drought resistance of plants in arid desert areas may be helpful.In this study,5 proline(Pro)concentrations(50,100,150,200,250 mg·L^(-1))were applied as a spray treatment to R.soongorica seedlings to investigate the extent of alleviation of damage caused by drought stress.Antioxidant enzyme activities,metabolic regulatory indicators,photosynthetic pigment levels and photosynthetic performance in leaves of R.soongorica seedlings were measured on the day before Pro treatments(day 0),and on the 1st,3rd,6th and 9th days after Pro treatments.A growth index of R.soongorica seedlings was compiled on the 9th day after Pro treatments,in order to elucidate the mechanism of action of Pro protection of plants under drought stress.It was found that the various exogenous Pro treatments had significant effects on the antioxidant enzyme system,metabolic regulation system,photosynthetic pigment levels,photosynthetic performance and growth status of R.soongorica seedlings.Among the measured traits,significant differences between year,among times of spraying,among Pro concentrations,and the interaction between treatment concentration and treatment time were detected.However,chlorophyll a/b(Chl a/b)showed no significant difference among treatment times,and soluble sugar(SS)showed no significant difference among treatment concentrations.The 100 mg·L^(-1)Pro treatment had the best overall effect.Soluble protein(SP),Pro,catalase activity(CAT)and peroxidase activity(POD)on the 9th day after the 100 mg·L^(-1)Pro treatment wer

关 键 词：外源脯氨酸 干旱胁迫 红砂 生理特性 缓解机理 

分 类 号：S793.9[农业科学—林木遗传育种]