Cloning of the Lycopene β-cyclase Gene in Nicotiana tabacum and Its Overexpression Confers Salt and Drought Tolerance

International Journal of Molecular Sciences

Yanmei Shi¹  Jinggong Guo⁵  Wei Zhang³  Lifeng Jin⁶  Pingping Liu⁶  Xia Chen⁶  Feng Li⁶  Pan Wei⁶  Zefeng Li⁶  Wenzheng Li²  Chunyang Wei⁴  Qingxia Zheng⁶  Qiansi Chen⁶  Jianfeng Zhang⁶  Fucheng Lin⁶  Lingbo Qu¹  John Hugh Snyder⁶  Ran Wang⁶ 

[1] College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou 450001, Henan, China;Yunnan Academy of Tobacco Agricultural Sciences, Kunming 650031, Yunnan, China;China National Tobacco Quality Supervision & Test Centre, Zhengzhou 450001, Henan, China;Staff Training Academy of CNTC, Zhengzhou 450008, Henan, China;Institute of Plant Stress Biology, State Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, Kaifeng 475004, Henan, China;National Tobacco Gene Research Center, Zhengzhou Tobacco Research Institute, Zhengzhou 450001, Henan, China;

关键词: lycopene β-cyclase;    carotenoid biosynthesis;    salt and drought tolerance;    reactive oxygen species;    abscisic acid;    Nicotiana tabacum;   

DOI  :  10.3390/ijms161226243

来源: mdpi

【 摘 要 】

Carotenoids are important pigments in plants that play crucial roles in plant growth and in plant responses to environmental stress. Lycopene β cyclase (β-LCY) functions at the branch point of the carotenoid biosynthesis pathway, catalyzing the cyclization of lycopene. Here, a β-LCY gene from Nicotiana tabacum, designated as Ntβ-LCY1, was cloned and functionally characterized. Robust expression of Ntβ-LCY1 was found in leaves, and Ntβ-LCY1 expression was obviously induced by salt, drought, and exogenous abscisic acid treatments. Strong accumulation of carotenoids and expression of carotenoid biosynthesis genes resulted from Ntβ-LCY1 overexpression. Additionally, compared to wild-type plants, transgenic plants with overexpression showed enhanced tolerance to salt and drought stress with higher abscisic acid levels and lower levels of malondialdehyde and reactive oxygen species. Conversely, transgenic RNA interference plants had a clear albino phenotype in leaves, and some plants did not survive beyond the early developmental stages. The suppression of Ntβ-LCY1 expression led to lower expression levels of genes in the carotenoid biosynthesis pathway and to reduced accumulation of carotenoids, chlorophyll, and abscisic acid. These results indicate that Ntβ-LCY1 is not only a likely cyclization enzyme involved in carotenoid accumulation but also confers salt and drought stress tolerance in Nicotiana tabacum.

【 授权许可】

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