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Scientia Silvae Sinicae ›› 2022, Vol. 58 ›› Issue (2): 125-132.doi: 10.11707/j.1001-7488.20220213

• Research papers • Previous Articles     Next Articles

Effects of S-Adenosylmethionine Decarboxylase Gene on Drought Tolerance of Populus alba × P. glandulosa '84K'

Junguang Yao,Ya Geng,Yijing Liu,Yi An*,Lichao Huang,Wei Zeng,Mengzhu Lu   

  1. State Key Laboratory of Subtropical Silviculture College of Forestry and Biotechnology, Zhejiang A & F University Hangzhou 311300
  • Received:2021-03-09 Online:2022-02-25 Published:2022-04-26
  • Contact: Yi An


Objective: Polyamines exist widely in plants, and are involved in the regulation of plant development and stress response. S-adenosylmethionine decarboxylase (SAMDC) is a key rate-limiting enzyme in the polyamine biosynthesis pathway. In this study, the role of SAMDC in poplar 84K (Populus alba × P. glandulosa '84K') under drought stress was analyzed using SAMDC overexpressing plants. This work will lay on important foundation for the elucidation of the role of polyamines in stress tolerance. Method: The nontransgenic(control) and transgenic PagSAMDC4a overexpressing poplar 84K plants growing in soil for 3 months were used and subjected to drought treatment to analyze phenotypic and physiological changes, including polyamines content, H2O2 content, relative water content of leaves, water loss rate of leaves, electrolytic leakage and so on. Result: The contents of endogenous spermidine and spermine in PagSAMDC4a-OE#3, PagSAMDC4a-OE#15 and PagSAMDC4a-OE#17 transgenic poplars were significantly higher than those in nontransgenic control, and the contents of endogenous putrescine, spermidine and spermine in PagSAMDC4a-OE#17 transgenic plant were 1.95, 3.43 and 1.32 times higher than those in control, respectively. Under normal conditions, compared with nontransgenic control, leaf phenotype, leaf relative water content and electrolytic leakage of overexpressing plants had no significant differences, while the water loss rate of PagSAMDC4a-OE#15 and PagSAMDC4a-OE#17 plants were significantly lower than that of control. Under drought stress, the leaves of nontransgenic plants were wilted, the relative water content decreased by 26.44% and the electrolytic leakage increased by 27.68%. However, PagSAMDC4a-OE plants grew normally, and the relative water content of overexpressing PagSAMDC4a-OE#3, PagSAMDC4a-OE#15 and PagSAMDC4a-OE#17 plants decreased by 10.9%, 3.66% and 1.33%, respectively. The overexpressing plants had low electrolytic leakage and a small variation. Under normal conditions, H2O2 contents of PagSAMDC4a transgenic plants were significantly reduced. Under the drought stress, the increase of H2O2 content of PagSAMDC4a overexpressing plants was significantly lower than that of nontransgenic plants, and the content variation from high to low was nontransgenic plant > PagSAMDC4a-OE#3 > PagSAMDC4a-OE#15 > PagSAMDC4a-OE#17. Conclusion: Overexpression of PagSAMDC4a gene can increase endogenous polyamines and decrease H2O2 content in poplar 84K, which can reduce the oxidative damage caused by drought stress and effectively alleviate the water stress damage suffered by the plant leaves, contributing to relieving the sensitivity of poplar to drought stress. Therefore, SAMDC4a could affect the changes of endogenous polyamines in response to drought stress.

Key words: Populus alba × P. glandulosa '84K', transgenic, SAMDC, polyamines, drought stress, H2O2, electrolytic leakage

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