New Material: Release Of The First Spatiotemporal Map Of Cotton Fiber Initial Development Single Cell

According to the Cotton Research Institute of the Chinese Academy of Agricultural Sciences, Ma Xiongfeng's research team has successfully constructed the first cotton fiber initial development map combining single cell transcriptome, spatial transcriptome and spatial metabolome, which can identify the expression pattern of cotton key genes and their relationship with metabolic pathways, and analyze the core regulatory mechanism during fiber development, It provides a new idea for further improving cotton fiber quality and increasing fiber yield. Relevant research results were published in the internationally renowned journal Nature Communication.

Cotton is the main raw material of textile industry. Cotton fiber is developed from a single cell on the surface of the outer epidermis of the seed. At the early stage of seed development, about 25% of the ovule epidermal cells differentiate into cotton fiber, and go through four different stages, namely the initial stage, the elongation and primary wall formation stage, the secondary wall thickening stage, and the fiber maturity stage. The first two stages determine the amount and length of fiber produced by each seed, which will directly affect the final cotton fiber yield; The latter two stages are related to cell wall thickening, which determines the fiber strength and fineness, and will directly affect the final cotton fiber quality.

However, the regulatory mechanisms that determine these developmental stages remain largely unknown. Therefore, analyzing the mechanism that determines the fate of cell development and regulates the initiation and extension of cotton fiber will provide a new way to improve cotton fiber yield and quality.

The research team used the upland cotton standard line TM-1 as research material to draw the single-cell transcriptome map spectrum, spatial transcriptome map spectrum and spatial metabolism map spectrum of cotton fiber early development, and constructed a multi-level dynamic regulation network of cotton fiber initial development, which can not only capture the gene expression pattern in the process of fiber cell development with high resolution, It can also reveal the metabolic changes closely related to gene expression, filling the technical gap in the research of fiber cell development at present.

It was reported that the team identified a number of key genes regulating cotton fiber initial development through further joint analysis of multiple genomics, and selected some of them for functional verification. It was found that BEE3 gene played a key role in regulating fiber initial development, and the overexpression of this gene could significantly promote the development of ovule epidermal cells into fiber cells.

At present, the team is conducting genetic analysis on the functional mechanism of the gene in Zhongmian 113, a high lint content cotton material, to explore excellent allelic variations, with a view to developing valuable molecular markers for the cultivation of high lint content cotton varieties. The unicellular data and spatial transcriptome data during the initial development of cotton fiber have been shared.