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应用生态学报 ›› 2022, Vol. 33 ›› Issue (7): 1901-1910.doi: 10.13287/j.1001-9332.202207.028

• 研究论文 • 上一篇    下一篇

褪黑素对盐碱复合胁迫下黄瓜幼苗光合特性和渗透调节物质含量的影响

吴鹏1,2, 吕剑1,2*, 郁继华1,2, 刘娜1, 李金武1, 金莉1, 金宁1, 王舒亚1   

  1. 1甘肃农业大学园艺学院, 兰州 730070;
    2甘肃省干旱生境作物学国家重点实验室, 兰州 730070
  • 收稿日期:2021-09-29 接受日期:2022-05-31 出版日期:2022-07-15 发布日期:2023-01-15
  • 通讯作者: *E-mail: lvjiangs@126.com
  • 作者简介:吴 鹏, 男, 1998年生, 硕士研究生。主要从事设施栽培与环境调控研究。E-mail: 1263524273@qq.com
  • 基金资助:
    甘肃省教育厅“双一流”科研重点项目(GSSYLXM-02)、中央引导地方科技发展专项(ZCYD-2020-5-2)、甘肃省民生科技专项(20CX9NA099)和甘肃农业大学伏羲青年英才培育基金项目(GAUfx-04Y03)资助。

Effects of melatonin on photosynthetic properties and osmoregulatory substance contents of cucumber seedlings under salt-alkali stress

WU Peng1,2, LYU Jian1,2*, YU Ji-hua1,2, LIU Na1, LI Jin-wu1, JIN Li1, JIN Ning1, WANG Shu-ya1   

  1. 1College of Horticulture, Gansu Agricultural University, Lanzhou 730070, China;
    2Gansu Provincial Key Laboratory of Aridland Crop Science, Lanzhou 730070, China
  • Received:2021-09-29 Accepted:2022-05-31 Online:2022-07-15 Published:2023-01-15

摘要: 为明确外源褪黑素(MT)对黄瓜盐碱胁迫的缓解效应,以‘新春四号’黄瓜为试材,采用复合盐碱(NaCl∶Na2SO4∶Na2CO3∶NaHCO3=1∶9∶1∶9)模拟胁迫,测定外源根施MT和盐碱胁迫下黄瓜叶片光合特性和渗透调节物质含量。结果表明: 与正常生长黄瓜幼苗相比,在40 mmol·L-1盐碱胁迫下,外源施加10 μmol·L-1 MT能够显著增加黄瓜幼苗叶片的叶绿素、可溶性糖和可溶性蛋白质含量,提高净光合速率、气孔导度、蒸腾速率、光系统Ⅱ最大光化学效率、实际光化学效率、表观光合电子传递速率和光化学淬灭系数,而胞间CO2浓度、非光化学淬灭系数、蔗糖、果糖、淀粉和脯氨酸含量减小了11.1%、13.8%、12.7%、27.5%、1.3%和32.8%,同时,碳同化关键酶核酮糖-1,5-二磷酸羧化/加氧酶、果糖-1,6-二磷酸酯酶活性显著升高,且Rubisco亚基(CsrbcSCsrbcL)、CsFBA、CsRCA、CsFBPase、CsTK的mRNA水平均下调表达。综上,外源MT能够提高盐碱胁迫下黄瓜幼苗的叶绿素、渗透调节物质含量、光合化学效率和碳同化关键酶活性,增强幼苗光合能力,减轻复合盐碱胁迫对植株的伤害。研究结果可为抗盐碱栽培提供理论依据。

关键词: 褪黑素, 盐碱复合胁迫, 黄瓜, 光合特性, 渗透调节物质

Abstract: To determine the mitigating effects of exogenous melatonin on salt-alkali stress in cucumber, we mea-sured photosynthetic characteristics and osmoregulatory substance content of cucumber leaves under salt-alkali stress, using ‘Xinchun 4’ cucumber as the test material and a salt-alkali complex (NaCl:Na2SO4:Na2CO3:NaHCO3 = 1:9:1:9) to simulate stress. The results showed that compared with the normal seedlings, the exogenous application of 10 μmol·L-1 melatonin significantly increased the contents of chlorophyll, soluble sugar, and soluble protein, as well as net photosynthetic rate, stomatal conductance, transpiration rate, photosystem Ⅱ maximum photochemical efficiency, actual photochemical efficiency, apparent photosynthetic electron transfer rate, and photochemical burst coefficient of cucumber seedlings under 40 mmol·L-1 salt-alkali stress, but decreased intercellular CO2 concentration, non-photochemical burst coefficient, and sucrose, fructose, starch, and proline contents by 11.1%, 13.8%, 12.7%, 27.5%, 1.3% and 32.8%, respectively. Moreover, the activities of key enzymes for carbon assimilation (including ribulose-1,5-bisphosphate carboxylase/oxygenase and fructose-1,6-bisphosphate esterase) were significantly increased, whereas the mRNA expression levels of Rubisco subunits (CsrbcS and CsrbcL), CsFBA, CsRCA, CsFBPase and CsTK were downregulated. In conclusion, exogenous melatonin could increase the contents of chlorophyll and osmoregulatory substance, photosynthetic chemical efficiency, and key carbon assimilation enzyme activities of cucumber seedlings under salt-alkali stress, thereby enhance photosynthetic capacity and reduce the stress-induced plant damage. The results would provide theoretical basis for anti-saline plant cultivation.

Key words: melatonin, salt-alkali stress, cucumber, photosynthetic property, osmoregulatory substance