百喜草根、叶在持续干旱胁迫下的生理响应（英文）

Physiological Response of Paspalum notatum’s Leaf and Root under Persistent Drought Stress

为探究干旱逆境下百喜草根、叶的联系与区别,研究以野生百喜草(Paspalum notatum)为研究试材,分别进行0(CK)、1、3、5、7、14、21、28 d的干旱胁迫处理,测定百喜草根、叶在不同时间干旱胁迫下渗透调节物质、抗氧化酶活性、丙二醛含量、细胞膜透性以及叶绿素含量的变化,对比百喜草根、叶在干旱胁迫下的生理反应。结果表明:随着干旱胁迫时间的延长,百喜草叶片和根系中可溶性蛋白含量、脯氨酸含量、丙二醛含量、细胞膜透性和CAT活性均呈逐渐上升趋势;可溶性糖、SOD活性呈先升后降趋势;POD呈逐渐下降趋势;3种叶绿素含量均呈先下降后上升最后又下降的变化趋势。干旱胁迫初期,SOD和CAT为百喜草根、叶的主要抗氧化物酶。随着胁迫加重,根系抗氧化物酶变为SOD,叶片为CAT和POD,干旱对根系的CAT和叶片的SOD、POD的影响显著。渗透调节和光合作用调节的部位主要是叶片。本研究为提高百喜草耐旱性提供了理论依据。

To investigate the correlation and difference between Paspalum notatum’s leaf and root under drought adversity,this study tested the physiological responses of wild Paspalum notatum’s leaf and root under 0(CK),1,3,5,7,14,21,and 28 d drought stress treatment.These physiological responses include osmotic regulating substance,antioxidant enzyme activity,malonaldehyde content,cell membrane permeability,and chlorophyll content.According to the results,the soluble protein content,proline concentration,malonaldehyde content,cell membrane permeability and CAT activity in Paspalum notatum’s leaf and root tended to increase with the prolongation of drought stress;the soluble sugar content and SOD activity first increased and then decreased;POD dropped gradually;the contents of chlorophyll a,b and total chlorophyll first declined,then mounted,and lastly dropped again.During the early stage of drought stress,SOD and CAT acted as the main antioxidant enzymes in Paspalum notatum’s leaf and root.However,with the aggravation of drought stress the predominant antioxidant enzymes became SOD in the root system whereas CAT and POD in the leaf.It implicates drought has a strong influence on root’s CAT and leaf’s SOD and POD.Leaf is the major organ regulating the osmosis and photosynthesis of Paspalum notatum.The findings can provide a useful theoretical basis for improving Paspalum notatum’s drought tolerance.