作 者：
刘建新;刘瑞瑞;刘秀丽;欧晓彬;贾海燕;王风琴;卜婷;李娜
单 位：
陇东学院生命科学与技术学院甘肃省陇东生物资源保护利用与生态修复重点实验室
关键词：
裸燕麦;盐碱胁迫;硫化氢;叶绿素荧光参数;光合生理
摘 要：
[目的]研究硫化氢(H2S)对盐碱胁迫下裸燕麦光合生理的影响,为揭示H2S增强裸燕麦耐盐碱性机理提供理论依据.[方法]以盆栽砂培裸燕麦品种'定莜9号'为材料,在抽穗期灌根施用50 mmol/L的盐碱溶液,同时喷施50 μmol/L H2S供体硫氢化钠(NaHS)溶液或结合灌根施用1 mmol/L H2S合成抑制剂羟胺(HA),研究H2S对盐碱混合胁迫下裸燕麦叶片叶绿素含量、光合气体交换参数、叶绿素荧光参数、叶黄素循环色素含量和相关基因相对表达量、卡尔文循环关键酶活性及植株生长的影响.[结果]盐碱混合胁迫下,喷施NaHS可显著缓解裸燕麦叶片光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)、气孔限制值(Ls)、水分利用效率(WUE)的下降和胞间CO2浓度(Ci)的提高;显著提高光化学淬灭系数(qL),紫黄质脱环氧化酶(VDE)和玉米黄质环氧化酶(ZEP)基因相对表达水平以及转酮醇酶(TK)活性;降低紫黄质(V)、单环氧玉米黄质(A)、玉米黄质(Z)含量和叶黄素循环的脱环氧化状态(A+Z)/(V+A+Z)以及1,5-二磷酸核酮糖羧化酶活化酶(RCA)、3-磷酸甘油醛脱氢酶(GAPDH)和景天庚酮糖-1,7-二磷酸酶(SBPase)活性;缓解裸燕麦根系和地上部干质量的下降幅度;而对裸燕麦叶片叶绿素含量、初始荧光(Fo)、最大荧光(Fm)、最大光化学量子产量[(Fm-Fo)/Fm]、实际光化学量子产量[Y(Ⅱ)]、非光化学淬灭系数(NPQ)、非调节性能量耗散量子产量[Y(NO)]、调节性能量耗散量子产量[Y(NPQ)]和相对电子传递速率(ETR),以及1,5-二磷酸核酮糖羧化酶(Rubisco)和果糖-1,6-二磷酸醛缩酶(FBA)活性无显著影响.增施HA后部分或完全逆转了上述喷施NaHS的作用.[结论]H2S通过加快叶黄素循环运转、提高光系统Ⅱ反应中心开放程度、协调卡尔文循环关键酶活性,缓解盐碱胁迫对裸燕麦光合作用和生长的抑制作用,从而增强裸燕麦耐受盐碱胁迫的能力.
译 名：
Effects of hydrogen sulfide on photosynthetic physiology of naked oat under saline-alkali stress
作 者：
LIU Jianxin;LIU Ruirui;LIU Xiuli;OU Xiaobin;JIA Haiyan;WANG Fengqin;BU Ting;LI Na;Gansu Key Laboratory of Protection and Utilization for Biological Resources and Ecological Restoration,College of Life Sciences and Technology,Longdong University;
关键词：
naked oat;;saline-alkali stress;;hydrogen sulfide;;chlorophyll fluorescence parameters;;photosynthetic physiology
摘 要：
【Objective】 This study investigated the effect of hydrogen sulfide(H_2S) on photosynthetic physiology of naked oat under saline-alkali stress to provide basis for revealing the mechanism of salt-alkali tolerance enhancement by H_2S.【Method】 Sand-cultivated naked oat variety ‘Dingyou 9' in pots were sprayed with 50 μmol/L H_2S donor sodium hydrosulfide(NaHS) solution with and without 1 mmol/L H_2S synthesis inhibitor hydroxylamine(HA) at heading stage.The effects of H_2S on chlorophyll content, photosynthetic gas exchange parameters, chlorophyll fluorescence parameters, key enzyme activities of Calvin cycle in leaves and plant growth of naked oats under 50 mmol/L saline-alkali mixed stress were studied.【Result】 Under saline-alkali mixed stress, spraying NaHS significantly alleviated the decrease in photosynthetic rate(P_n),stomatal conductance(G_s),transpiration rate(T_r),stomatal limit value(L_s) and water use efficiency(WUE) and the increase of intercellular CO_2 concentration(C_i) in naked oat leaves.It significantly increased photochemical quenching coefficient(qL),relative expression levels of violaxanthin de-epoxidase(VDE) and zeaxanthin epoxidase(ZEP) genes and activity of transketolase(TK),while significantly reduced contents of violaxanthin(V),antheraxanthin(A) and zeaxanthin(Z),de-epoxidation state of xanthin circle(A+Z)/(V+A+Z) and activities of ribulose-1,5-bisphophate carboxylase activase(RCA),glyceraldehyde-3-phosphate dehydrogenase(GAPDH) and sedoheptulose-1,7-bisphosphatase(SBPase).It also mitigated the decline in dry weight of roots and shoots of naked oats, but had no significant effect on chlorophyll content, initial fluorescence(F_o),maximum fluorescence(F_m),maximum photochemical quantum yield [(F_m-F_o)/F_m],actual photochemical quantum yield [Y(Ⅱ)],non-photochemical quenching coefficient(NPQ),unregulated energy dissipation quantum yield [Y(NO)],regulated energy dissipation quantum yield [Y(NPQ)],relative electron transport rate(ETR) and activities of ribulose-1,5-bisphophate carboxylase(Rubisco) and fructose-1,6-bisphosphate aldolase(FBA) in leaves.The addition of HA partially or completely reversed the effects of NaHS spraying.【Conclusion】 H_2S alleviated the inhibition of photosynthesis and growth of naked oats under saline-alkali stress and enhanced the ability of naked oats to tolerate saline-alkali stress by accelerating xanthophylls cycle, improving opening degree of photosystem Ⅱ reaction center and coordinating activities of key enzymes related to the Calvin cycle.
