GbKCS14 synthesizes VLCFAs to respond to low temperatures during fuzz initial stage of Gossypium barbadense

• Published in: Industrial crops and products Vol. 217; p. 118875
• Main Authors: Cao, Yuefen, Zhao, Xuan, Tang, Mengling, Sun, Chendong, Ding, Mingquan, Song, Yuchen, Lan, Jiakai, Gao, Zhenzhe, Rong, Junkang
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.10.2024
• Subjects: Cotton; Epigenetics; Fiber; KCS; VLCFA; Epigenetics; KCS; Cotton; Fiber; VLCFA
• ISSN: 0926-6690; 1872-633X
• DOI: 10.1016/j.indcrop.2024.118875

Temperature is a crucial climatic determinant influencing the growth and development of cotton. In Gossypium barbadense, exposure to low temperatures for 3–5 days after flowering leads to an elevated incidence of fuzzless seeds and a significant reduction in fuzz fibers. We analyzed the transcriptome data of ovules under high- and low temperatures, revealing temperature-dependent regulation of multiple β-ketoacyl-CoA synthase (KCS) family genes. GbKCS14 exhibited heightened activity during the fuzz initiation stage under low-temperature conditions. Overexpression of GbKCS14 in Arabidopsis resulted in increased shoot elongation and significantly higher levels of very-long-chain fatty acids (VLCFA) C20:0 and C24:0 compared to wild-type plants, indicating that GbKCS14 can catalyze the synthesis of C20:0 and C24:0. C20:0 and C24:0 were subsequently proved to promote fiber development at low temperatures. The content of unsaturated VLCFAs, C20:1 and C20:2, significantly increased in ovules treated at low temperatures. The methylation level of the GbKCS14 promoter region was significantly regulated by temperature. Yeast one-hybrid experiments showed that the histone demethylase GbREF6 could bind to the −370 nt to −359 nt position (AAAAACAGAGTA) upstream of GbKCS14. We suggested that the transcription of GbKCS14 is temperature-dependent and dual-regulated by DNA methylation and histone methylation. This regulatory pattern of GbKCS14 may be a protective mechanism for cotton under low temperatures by increasing the levels of VLCFAs and their unsaturation. •Very-long-chain fatty acids (VLCFA) responses to low temperature and reverse the inhibitory effect of low temperature on fiber growth.•In ovules, the contents of VLCFAs C20:1, C20:2, and C24:0 increase during the fuzz initiation stage at low temperature. Simultaneously, a β-ketoacyl-CoA synthase gene GbKCS14 that governing the synthesis of very-long-chain fatty acids (VLCFA) C20:0 and C24:0 is activated strongly.•Low temperatures may promote DNA demethylation and histone demethylation to activate GbKCS14 expression that stimulates the synthesis of VLCFAs to reduce the impact on the initiation of fuzz fibers caused by low temperatures, and promote the conversion of saturated fatty acids to unsaturated fatty acids to help cells resist cold.