Comparative Transcriptomic Analysis Identifies Key Cellulose Synthase Genes (CESA) and Cellulose Synthase-like Genes (CSL) in Fast Growth Period of Flax Stem (Linum Usitatissimum L.)

ABSTRACT

The cellulose synthase gene superfamily is vital for cell wall biogenesis during plant growth, particularly for flax fiber development. This study performed asequencing search of key CESA and CSL genes from several flax stem parts at different fiber development stages by comparing RNA-Seq. Quantitative RT-PCR was used to validate the expression of these genes. This study revealed that CESA4 genes (Lus10008225.g and Lus10008226.g), CESA6 genes (Lus10006161.g and Lus10041063.g), CESA8 genes (Lus10007296.g and Lus10029245.g), CSLD4 gene (Lus10026568.g), CSLE1 (Lus10016625.g) and CSLG genes (Lus10023056.g and Lus10023057.g) were specifically expressed in stem below the snap point where fibers is increased amounts of secondary cell wall deposition. LusCESA4 genes, LusCESA8, genes and LusCSLD4 gene were specifically expressed in fiber development stage during the fast growth period of flax plants. Based on GO and KEGG analyses, it was found that genes involved in pathways of cellulose microfibril organization, galactosyl transferase activity and galactose metabolism were specifically enriched in the stem tissue of the fiber development stage. Other genes involved in cellulose biosynthesis and cell wall development were also analyzed and discussed. The results will provide an important foundation for understanding fiber cell wall biogenesis, particularly the roles of LusCESAs and LusCSLs in the process of fiber development.

摘要

纤维素合成酶基因超家族在植物生长过程中对细胞壁生物发生至关重要, 尤其是对亚麻纤维的发育. 本研究通过比较RNA-Seq, 对不同纤维发育阶段的几种亚麻茎段的关键CESA和CSL基因进行了测序搜索. 定量RT-PCR用于验证这些基因的表达. 本研究揭示了CESA4基因 (Lus10008225.g和Lus10008226.g)、CESA6基因(Lus10006161.g和Lus10041063.g)、CESA8基因(Lus10007296.g和Lus10029245.g)、CSLD4基因 (Lus10026568.g)、CSLE1基因(Lus10016625.g)和CSLG基因 (Lus10023056.g和LUS1003057.g) 在茎中特异性表达, 位于断裂点以下, 纤维数量增加, 次生细胞壁沉积. LusCESA4基因、LusCESA8基因和LusCSLD4基因在亚麻植株快速生长期的纤维发育阶段特异表达. 基于GO和KEGG分析, 发现参与纤维素微纤丝组织、半乳糖基转移酶活性和半乳糖代谢途径的基因在纤维发育阶段的茎组织中特别富集. 其他与纤维素生物合成和细胞壁发育有关的基因也进行了分析和讨论. 这些结果将为纤维细胞壁生物发生提供重要的基础, 特别是LuScas和LuScLSs在纤维发育过程中的作用.

KEYWORDS:

• Linum usitatissimum l.
• cellulose synthase gene
• cellulose synthase-like genes
• cell wall biogenesis
• Transcriptomic
• Gene

关键词:

• 纤维素合成酶基因
• 纤维素合成酶样基因
• 细胞壁生物发生
• 转录组学
• 基因

Acknowledgments

We thank all the staff in our lab for providing useful suggestions and technical assistance. We are very grateful to the editor and reviewers for providing constructive comments for the improvement of our manuscript. We also thank for the fund supporting by the National Natural Science Foundation of China.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Availability of data and materials

We have deposited our transcriptome data in Sequence Read Archive (SRA) (http://www.ncbi.nlm.nih.gov/sra/), the accession number for our submission is: PRJNA723911.

Additional information

Funding

This work was supported by National Natural Science Foundation of China (grant number 31771852), China Agriculture Research System Fund (grant number CARS-16-E13) and the Agricultural Science and Technology Innovation Programin Chinese Academy of Agricultural Sciences (grant number CAAS-ASTIP-IBFC06). Funding bodies were not involved in the design of the study, collection of data, analysis, and interpretation of data or in writing the manuscript.