Journal of Integrative Agriculture ›› 2024, Vol. 23 ›› Issue (6): 1864-1878.DOI: 10.1016/j.jia.2023.05.013

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异源表达亚麻硬脂酰-酰基载体蛋白脱饱和酶基因SAD1和SAD2促进甘蓝型油菜种子油酸积累并提高幼苗抗寒和抗旱能力

  

  • 收稿日期:2023-03-20 接受日期:2023-04-21 出版日期:2024-06-20 发布日期:2024-05-29

Heterogeneous expression of stearoyl-acyl carrier protein desaturase genes SAD1 and SAD2 from Linum usitatissimum enhances seed oleic acid accumulation and seedling cold and drought tolerance in Brassica napus

Jianjun Wang*, Yanan Shao*, Xin Yang, Chi Zhang, Yuan Guo, Zijin Liu, Mingxun Chen#   

  1. State Key Laboratory of Crop Stress Biology for Arid Areas/National Yangling Agricultural Biotechnology & Breeding Center/Shaanxi Key Laboratory of Crop Heterosis/College of Agronomy, Northwest A&F University, Yangling 712100, China

  • Received:2023-03-20 Accepted:2023-04-21 Online:2024-06-20 Published:2024-05-29
  • About author:#Correspondence Mingxun Chen, E-mail: cmx786@nwafu.edu.cn * These authors contributed equally to this study.
  • Supported by:
    This work was supported by the National Science and Technology Innovation 2030 of China (2022ZD04010), the National Key Research and Development Program of China (2022YFD1200400), the Key Research and Development Program of Shaanxi Province, China (2022NY-158), the Ph D Start-up Fund of Northwest A&F University, China (Z1090121052), and a grant from the Yang Ling Seed Industry Innovation Center, China (K3031122024).

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摘要：

亚麻(Linum usitatissimum L.)是一种多用途作物，其种子含有丰富的不饱和脂肪酸。硬脂酰-酰基载体蛋白脱饱和酶(SAD)是脂肪酸合成通路中催化油酸合成的关键酶，同时参与调控植物对外界胁迫的抵抗能力。然而，关于亚麻LuSAD基因的功能研究尚未见报道。本研究从亚麻品种‘陇亚10号’中克隆获得LuSAD1和LuSAD2基因的全长编码区序列，将其在拟南芥野生型背景下异源表达，发现LuSAD1和LuSAD2促进种子总脂肪酸和油酸的生物合成，且LuSAD2导致拟南芥株型发生变化。进一步研究发现，在甘蓝型油菜品种‘中双11’背景下过量表达LuSAD1和LuSAD2均促进种子总脂肪酸和油酸的生物合成。此外，LuSAD1和LuSAD2通过提高抗氧化物酶活性和非酶类抗氧化物质的含量、降低对细胞膜的损伤进而增强幼苗对寒冷和干旱胁迫的抵抗能力。因此，亚麻LuSAD1和LuSAD2可以作为基因工程技术提高油料作物产油量和非生物胁迫抵抗能力的潜在靶标。

Abstract:

Flax (Linum usitatissimum L.) is a versatile crop and its seeds are a major source of unsaturated fatty acids.  Stearoyl-acyl carrier protein desaturase (SAD) is a dehydrogenase enzyme that plays a key role in oleic acid biosynthesis as well as responses to biotic and abiotic stresses.  However, the function of SAD orthologs from L. usitatissimum has not been assessed.  Here, we found that two LuSAD genes, LuSAD1 and LuSAD2, are present in the genome of L. usitatissimum cultivar ‘Longya 10’.  Heterogeneous expression of either LuSAD1 or LuSAD2 in Arabidopsis thaliana resulted in higher contents of total fatty acids and oleic acid in the seeds.  Interestingly, ectopic expression of LuSAD2 in A. thaliana caused altered plant architecture.  Similarly, the overexpression of either LuSAD1 or LuSAD2 in Brassica napus also resulted in increased contents of total fatty acids and oleic acid in the seeds.  Furthermore, we demonstrated that either LuSAD1 or LuSAD2 enhances seedling resistance to cold and drought stresses by improving antioxidant enzyme activity and nonenzymatic antioxidant levels, as well as reducing membrane damage.  These findings not only broaden our knowledge of the LuSAD functions in plants, but also offer promising targets for improving the quantity and quality of oil, and the abiotic stress tolerance of oil-producing crops, through molecular manipulation.

Key words: LuSAD ,  oleic acid ,  cold tolerance ,  drought tolerance ,  Linum usitatissimum ,  Brassica napus