中文摘要：

【目的】生姜具喜温怕热的特性，生产中极易遭受高温伤害。文章旨在通过研究高温胁迫条件下外源NO与多胺代谢的关系，以及对PSII的调控作用，探讨外源NO缓解生姜高温胁迫的生理机制。【方法】以砂培‘莱芜大姜’为试材，置光周期12h／12h、昼夜温度28℃／18℃和38℃／28℃的光照培养箱内，分别用0．1mmol·L-1硝普钠（SNP，NO供体）和铁氰化钠（SF，SNP释放NO后的产物）处理植株根系，分别于处理后0、5、10、15和20d测定功能叶片的相对含水量、叶绿素含量、电解质渗透率、叶绿素荧光参数及多胺代谢途径相关指标。【结果】高温胁迫导致生姜叶片电解质渗透率增加，相对含水量及叶绿素含量降低；随着高温胁迫时间的延长，叶片最大光化学效率（Fv／Fm）、实际光化学效率（φDPSII）、天线转化效率（Fv‘／Fm，）、光化学猝灭系数（qP）和P持续降低，非光化学猝灭（NPQ）、β／α-1和D显著升高；主要表现为PsII反应中心的光化学活性降低，即能量代谢途径由光化学反应转为非光化学反应。高温胁迫下游离态、结合态多胺含量先升后降，束缚态多胺持续上升，腐胺／多胺（Put／PAs）比值显著升高。外源添加NO可恢复叶片相对含水量和叶绿素含量，降低电解质渗透率，促使叶绿素荧光参数趋于正常水平，提高高温胁迫下多胺代谢水平，恢复Put／Phs比值。【结论】38℃／28℃的高温胁迫导致生姜叶片受损，PsII功能紊乱，多胺代谢异常；外源添加0．1mmo1·L-1SNP可降低高温胁迫下生姜叶片损伤程度，维护PsII的正常生理功能，维持多胺的正常代谢，进而提高生姜植株的耐热性。

英文摘要：

[ Objective ] Ginger is a thermophilic vegetable crop with the characteristics of not tolerating high temperature, which is easily damaged by high temperature. To investigate the relationship between exogenous nitric oxide and polyamine metabolism, as well as the regulation effect on PSII, mitigation effect of heat stress on ginger by nitric oxide was studied. [Method] ＇Laiwu Big Ginger＇ was sandy cultured in a climate chamber under 12h/12h photoperiod, 28C/18C （normal） and 38C/28C （heat stress） conditions. Ginger root was treated with 0.1 mmol＇L＂1 sodium nitroprussiate （an nitric oxide donor） and sodium ferricyanide （reactant of SNP after releasing NO）. Relative water content, chlorophyll concentration, electrolyte leakage, chlorophyll fluorescence parameters and polyamine metabolism of ginger leaves were investigated on 0, 5, 10, 15 and 20 d after treatment. [Result] Electrolyte leakage significantly increased with prolonging stressed time, while relative water content and chlorophyll concentrationsignificantly decreased. Chlorophyll fluorescence parameters including Fv/Fm, qbpsH, Fv＇/Fm＇ qP and P decreased, and NPQ, {]/t-1 and D increased. Main pattern of PSII was shown that its photochemical activity of PSII was decreased for the energy metabolism pathway shifting from photochemical to non-photochemical activity. Under heat stress, free and conjugated polyamines were significantly accumulated and then decreased in different treatment times. Insoluble bound polyamine and Put/PAs ratio kept an increasing trend with prolonging stressed time. Relative water content, chlorophyll concentration, electrolyte leakage of ginger leaves was recovered by exogenous application of nitric oxide, which regulated chlorophyll fluorescence parameters to normalization. Also nitric oxide application improved polyamine metabolism to reduce Put/PAs ratio. [ Conclusion ] Disordered polyamine metabolism, damaged ginger leaves and PSII were shown under 38C/28C conditions. Significant heat stress mitigation b