摘要
以冬小麦品种‘豫农211’为材料,通过设置持续12 d控水和干旱后复水2 d盆栽实验,研究根施15 mmol·L^-1丙酸溶液处理下小麦植株形态、叶片相对含水量、电导率、丙二醛含量对干旱胁迫的响应,以及控水和复水过程中叶片脯氨酸含量及其关键代谢酶活性的动态变化,以探明外源丙酸提高小麦抗旱性的脯氨酸代谢机制。结果表明:(1)在干旱胁迫条件下(土壤相对含水量降至20%),根施丙酸处理可显著提高小麦叶片相对含水量,并显著降低叶片相对电导率和丙二醛含量(P<0.05);丙酸处理组小麦幼苗萎蔫程度明显低于同期对照,地上部生物量积累量比对照增加了13.3%。(2)根施丙酸处理的小麦叶片脯氨酸积累量在轻度干旱胁迫下(土壤相对含水量降至45%~55%)显著高于对照,且随着干旱胁迫程度的加剧(土壤相对含水量降至20%以下)脯氨酸含量仍能稳定维持在正常水平(300μg·g^-1左右),而对照叶片脯氨酸含量则呈急剧上升的趋势;复水处理后,丙酸处理的小麦植株中叶片脯氨酸含量能迅速恢复至正常水平。(3)在整个控水至复水过程中,小麦叶片脯氨酸合成关键酶△1-吡咯啉-5-羧酸合成酶(P5CS)和鸟氨酸σ-氨基转移酶(σ-OAT)活性均呈现先升后降的变化趋势,吡咯啉-5-羧酸还原酶(P5CR)活性呈现先降后升的变化趋势,而脯氨酸降解关键酶脯氨酸脱氢酶(PDH)活性呈增加趋势。研究认为,在干旱胁迫条件下,根施丙酸能够通过调控脯氨酸代谢过程中的合成和降解途径关键酶活性来维持叶片细胞内脯氨酸水平稳定,有效减轻叶片水分散失和过氧化伤害程度,从而提高冬小麦幼苗的抗旱性。
Taking winter wheat cultivar‘Yunong 211’as materials,we carried out a pot experiment that set up to control water for 12 days and rewater for 2 days after drought to study the effects of root application of 15 mmol·L^-1 propionic acid on plant morphology,leaf relative water content,electrical conductivity,malondialdehyde content and the dynamic changes of leaf proline content and its key metabolic enzyme activities,to explore the mechanism of proline metabolism of exogenous propionic acid in improving drought resistance of wheat.The results showed that:(1)under drought stress(the relative water content of soil decreased to 20%),the root application of propionic acid could significantly increase the relative water content of wheat leaves,and reduce the relative conductivity and malondialdehyde content of wheat leaves.The wilting degree of wheat seedlings treated with propionic acid was significantly lower than that of control,and the biomass accumulation in the shoot increased by 13.3%(P<0.05).(2)Under mild water stress(soil relative water content decreased to 45%-55%),the root propionic acid treatment led to a significant accumulation of proline than control.With the increase of drought stress(soil relative water content decreased to below 20%),it could still maintain at the normal level(about 300μg·g^-1),while the proline content in control leaves increased sharply;and the proline content in leaves of wheat treated with propionic acid could recover to normal level rapidly.(3)During the whole process from water control to rewatering,the activities of the key enzymesΔ1-pyrroline-5-carboxylate synthetase(P5CS)and ornithine aminotransferase(σ-OAT)of proline biosynthesis increased firstly and then decreased.The activity of pyrroline-5-carboxylic acid reductase(P5CR)decreased firstly and then increased,while the activity of proline dehydrogenase(PDH),the key enzyme of proline degradation,increased.These results suggested that under drought stress,applying propionic acid to roots could regulate the key enzyme
作者
李永珍
范合琴
张早立
连延浩
任永哲
辛泽毓
王志强
林同保
LI Yongzhen;FAN Heqin;ZHANG Zaoli;LIAN Yanhao;REN Yongzhe;XIN Zeyu;WANG Zhiqiang;LIN Tongbao(College of Agronomy, Henan Agricultural University, Zhengzhou 450046, China)
出处
《西北植物学报》
CAS
CSCD
北大核心
2020年第4期649-657,共9页
Acta Botanica Boreali-Occidentalia Sinica
基金
国家重点研发计划项目(2016YFD0300205)
河南省高校重点科研项目(15B210005)。
关键词
小麦
干旱
丙酸
脯氨酸
代谢酶
wheat
drought
propionic acid
proline
metabolic enzymes
