ACTA AGRICULTURAE BOREALI-SINICA ›› 2021, Vol. 36 ›› Issue (6): 96-105. doi: 10.7668/hbnxb.20192390

Special Issue: Oil crops Biotechnology Hot Article

• Tillage & Cultivation·Physiology & Biochemistry • Previous Articles     Next Articles

Physiological Response Mechanism to High Temperature Stress in Different Heat-Tolerant Genotypes of Sesame Seedlings

SU Xiaoyu1,2,3, GAO Tongmei1,2,3, LI Feng1,2,3, WEI Libin1,2,3, TIAN Yuan1,2,3, WANG Dongyong1,2,3, ZHU Songtao4, WEI Shuangling1,2,3   

  1. 1. Sesame Research Center, Henan Academy of Agricultural Sciences, Zhengzhou 450002, China;
    2. Henan Key Laboratory of Specific Oilseed Crops Genomics, Zhengzhou 450002, China;
    3. Huang-Huai-Hai Key Laboratory of Oil Crops by Ministry of Agriculture, Zhengzhou 450002, China;
    4. Agriculture and Rural Affairs Bureau of Shangshui County, Shangshui 466100, China
  • Received:2021-08-04 Published:2021-12-28

Abstract: In order to explore the physiological response to high temperature stress in sesame,the seedlings of two different sesame genotypes,Zhengtaizhi No.3(heat tolerance) and SP19(heat sensitivity),were treated at 45℃ as high temperature stress and 30℃ as control for 10 days.The growth phenotype,antioxidant capacity,photosynthetic parameters and microstructure of stomata and chloroplast of the seedlings were analyzed.The results showed that with the extension of stress time,the plant height,leaf length,leaf width,relative water content,chlorophyll content,Fv/Fm,φPSⅡ,ETR(Ⅱ),net photosynthetic rate(Pn),transpiration rate(Tr) and stomatal conductance(Gs) decreased,while the relative electrical conductivity,reactive oxygen species and malondialdehyde content increased significantly,and the change range of SP19 was larger than that of Zhengtaizhi No.3.The antioxidant enzymes(superoxide dismutase,peroxidase and catalase) activities in the plants treated with high temperature were higher than that of control.Compared to SP19,the antioxidant enzyme activity was higher in Zhengtaizhi No.3.Microstructure observation showed that under high temperature stress for 10 days,the stomatal aperture was decreased for both varieties,and the stomata of SP19 were completely closed,while Zhengtaizhi No.3 stomata were not completely closed.Meanwhile,chloroplasts became round and moved to the middle of cells,grana accumulation thickened,lamella fractured and osmiophilic granules increased in Zhengtaizhi No.3,and the structural stability of chloroplasts of Zhengtaizhi No.3 was higher than that of SP19.In conclusion,the antioxidant enzyme activity,membrane lipid peroxidation,chloroplast structural stability and the photosystem Ⅱ(PSⅡ) activity are the key factors to affect heat tolerance of sesame seedlings.

Key words: Sesame, High temperature stress, Photosynthesis, Chloroplast, Autioxidant enzyme activities

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Cite this article

SU Xiaoyu, GAO Tongmei, LI Feng, WEI Libin, TIAN Yuan, WANG Dongyong, ZHU Songtao, WEI Shuangling. Physiological Response Mechanism to High Temperature Stress in Different Heat-Tolerant Genotypes of Sesame Seedlings[J]. ACTA AGRICULTURAE BOREALI-SINICA, 2021, 36(6): 96-105. doi: 10.7668/hbnxb.20192390.

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