CAJ | 학술논문

一氧化氮( Nitric oxide, NO)作为一种气体信号分子,不仅参与植物生长和发育等生理代谢过程,而且对植物的抗逆性也具有一定的作用。以20%聚乙二醇PEG 6000溶液模拟干旱胁迫,100μmol/L SNP为NO供体,研究了NO对干旱胁迫下君迁子幼苗叶片电子传递、光能分配和反应中心开放等PSⅡ功能的影响,以探讨干旱条件下NO对植物光合作用的调节作用。结果表明：干旱胁迫的第1 d和第5 d,SNP处理增加了干旱胁迫下君迁子幼苗叶片的水势(ψw )和叶绿素含量,且恢复了PSⅡ的电子传递速率(ΦPSⅡ和Fm/Fo )及潜在活性( Fv/Fo )；干旱胁迫降低了光化学淬灭系数( qp )和PSⅡ反应中心捕获光能的转化效率,但SNP处理增加了捕获光能用于光化学反应的比例( Pr ),进而增加了PSⅡ开放反应中心的活性,促进了非辐射能量的散耗,减轻甚至避免了过剩光能对光合机构的破坏。因此,干旱条件下外源NO供体可能参与了君迁子幼苗叶片PSⅡ对光能的利用。
일양화담( Nitric oxide, NO)작위일충기체신호분자,불부삼여식물생장화발육등생리대사과정,이차대식물적항역성야구유일정적작용。이20%취을이순PEG 6000용액모의간한협박,100μmol/L SNP위NO공체,연구료NO대간한협박하군천자유묘협편전자전체、광능분배화반응중심개방등PSⅡ공능적영향,이탐토간한조건하NO대식물광합작용적조절작용。결과표명：간한협박적제1 d화제5 d,SNP처리증가료간한협박하군천자유묘협편적수세(ψw )화협록소함량,차회복료PSⅡ적전자전체속솔(ΦPSⅡ화Fm/Fo )급잠재활성( Fv/Fo )；간한협박강저료광화학쉬멸계수( qp )화PSⅡ반응중심포획광능적전화효솔,단SNP처리증가료포획광능용우광화학반응적비례( Pr ),진이증가료PSⅡ개방반응중심적활성,촉진료비복사능량적산모,감경심지피면료과잉광능대광합궤구적파배。인차,간한조건하외원NO공체가능삼여료군천자유묘협편PSⅡ대광능적이용。
Nitric Oxide ( NO) has emerged as a key signal molecule involved in physiological metabolic processes of growth and development, and induced resistance to various abiotic stresses in plants. To characterize the role of NO in drought tolerance induced by polyethylene glycol ( PEG) , sodium nitroprusside ( SNP) of 100μmol/L as exogenous NO donor was applied to study the biologically protective effects of NO at a low concentration on PSⅡfunctions in Diospyros lotus seed-lings hydroponically grown under 20% PEG stress. Under drought stress, on the first and fifth days of SNP treatment, the wa-ter potential (ψw ) and chlorophyll content were increased, the electron transport velocity (ΦPSⅡand Fm/Fo ) and potential activity of PSⅡreaction centers (Fv/Fo) were maintained in favorable level. The photochemical quenching coefficient (qp) and the transformation efficiency of light energy captured by PSⅡsystem declined under drought stress, while SNP treatment raised the proportion of captured light energy used in photochemical reaction (Pr), thus promoted the activity of PSⅡreaction center, increased the dissipation of non-radiactive energy, and consequently alleviated and avoided the destruction of photo-synthetic apparatus by excessive light energy. In conclusion, SNP may participate in the utilization of light energy in PSⅡof Diospyros lotus seedlings under drought stress by PEG.