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应用生态学报 ›› 2017, Vol. 28 ›› Issue (5): 1603-1610.doi: 10.13287/j.1001-9332.201705.009

• 目次 • 上一篇    下一篇

黄瓜幼苗光合作用对高温胁迫的响应与适应

孙胜楠, 王强, 孙晨晨, 刘丰娇, 毕焕改, 艾希珍*   

  1. 山东农业大学园艺科学与工程学院/作物生物学国家重点实验室/农业部黄淮地区园艺作物生物学与种质创制重点开放实验室/山东省果蔬优质高效生产协同创新中心, 山东泰安 271018
  • 收稿日期:2016-09-28 修回日期:2017-02-13 发布日期:2017-05-18
  • 通讯作者: *E-mail: axz@sdau.edu.cn
  • 作者简介:孙胜楠, 男, 1990年生, 硕士研究生. 主要从事蔬菜栽培与生理生态研究. E-mail: 303689426@qq.com
  • 基金资助:
    本文由山东省现代农业产业技术体系建设专项(SDAIT-05-10)资助

Response and adaptation of photosynthesis of cucumber seedlings to high temperature stress

SUN Sheng-nan, WANG Qiang, SUN Chen-chen, LIU Feng-jiao, BI Huan-gai, AI Xi-zhen*   

  1. College of Horticulture Science and Engineering, Shandong Agricultural University/State Key Laboratory of Crop Biology/Ministry of AgricultureKey Laboratory of Horticultural Crop Biology and Germplasm Innovation/Collaborative Innovation Center of Shandong Province with High Quality and Efficient Production of Fruit and Vegetable, Tai’an 271018, Shandong, China
  • Received:2016-09-28 Revised:2017-02-13 Published:2017-05-18
  • Contact: *E-mail: axz@sdau.edu.cn
  • Supported by:
    This work was supported by the Special Fund of Modern Agriculture Industrial Technology System of Shandong Province in China (SDAIT-05-10)

摘要: 以‘津优35号’黄瓜幼苗为试材,研究高温(HT: 42 ℃/32 ℃)和亚高温(SHT: 35 ℃/25 ℃)胁迫对黄瓜幼苗光合作用及生长量的影响.结果表明: 高温、亚高温明显抑制幼苗生长.随着胁迫时间的延长,黄瓜幼苗叶片的光合速率(Pn)逐渐降低,胞间CO2浓度(Ci)趋于升高,气孔导度(gs)、蒸腾速率(Tr)、光呼吸速率(Pr)和暗呼吸速率(Dr)先上升后下降,高温、亚高温引起Pn降低的主要原因是非气孔限制.高温、亚高温可使黄瓜幼苗叶片的暗下光系统Ⅱ最大光化学效率(Fv/Fm)、光下实际光化学效率(ΦPSII)、光化学猝灭系数(qP)和电子传递效率(ETR)显著降低,初始荧光(Fo)和非化学猝灭系数(NPQ)逐渐升高.随着胁迫时间的延长,HT处理的RuBP羧化酶(RuBPCase)和Rubisco活化酶(RCA)活性及其mRNA表达量逐渐降低,而SHT处理的胁迫初期变化不大,3 d后趋于降低;HT和SHT处理的景天庚酮糖-1,7-二磷酸酶(SBPase)和果糖-1,6-二磷酸醛缩酶(FBA)活性与mRNA表达均呈先升高后降低趋势.可见,适宜光强下短时亚高温处理黄瓜幼苗不会产生明显光抑制,高温胁迫会对其PSⅡ反应中心造成严重损伤;光合酶受高温胁迫诱导,但其诱导效应与温度升高幅度和高温持续时间有关.

Abstract: Cucumber seedlings (Cucumis sativus Jinyou 35) were used to study the effects of high temperature (HT: 42 ℃/32 ℃) and sub-high temperature (SHT: 35 ℃/25 ℃) on its photosynthesis and growth. The results showed that the growth of cucumber seedlings was dramatically inhibited by the high and sub-high temperature stresses. The photosynthetic rate (Pn) was gradually reduced, while intercellular CO2 concentration (Ci) was increased as heat stress lasted. Under heat stress, stomatal conductance (gs), transpiration rate (Tr), photorespiration rate (Pr) and dark respiration rate (Dr) showed a trend from rise to decline in cucumber seedlings, which implied that heat-induced decline of photosynthesis was mainly due to non-stomatal limitation. Maximal photochemical efficiency of PSⅡ in darkness (Fv/Fm), actual photochemical efficiency (ΦPS), photochemical quenching (qP) and electron transport rate (ETR) were severely hampered, while initial fluorescence (Fo) and non-chemical quenching (NPQ) were increased as a result of high and sub-high temperature stresses. Under extended high temperature stress, the activities of RuBP carboxylase (RuBPCase) and Rubisco activase (RCA) as well as the mRNA abundance of Rubisco and RCA were in the trend of decrease, while they were reduced 3 days following the sub-high temperature treatment. The activities and mRNA expressions of sedoheptulose-1,7-bisphosphatase (SBPase) and fructose 1,6-bisphosphate aldolase (FBA) increased initially, but decreased afterwards under heat stress. Taken together, our data suggested that short-term sub-high temperature did not cause photoinhibition under optimal light conditions, however, high temperature led to severe damage to PSⅡ reaction center in cucumber seedlings. The photosynthetic enzymes were induced by high temperature stress and the induction was affected by temperature and stress duration.