Cotton fiber elongation requires the transcription factor GhMYB212 to regulate sucrose transportation into expanding fibers

Abstract

Summary Cotton is white gold across the globe and composed of fiber cells derived from the outer integument of cotton ovules. Fiber elongation uses sucrose as a direct carbon source. The molecular mechanism transcriptionally controlling sucrose transport from ovules into the elongating fibers remains elusive. In this study the involvement of GhMYB212 in the regulation of sucrose transportion into expanding fibers was investigated. GhMYB212 RNAi plants (GhMYB212i) accumulated less sucrose and glucose in developing fibers, and had shorter fibers and a lower lint index. RNA‐seq and protein−DNA binding assays revealed that GhMYB212 was closely linked to the pathways of sucrose and starch transportation and metabolism, directly controling the expression of a sucrose transporter gene GhSWEET12. GhSWEET12 RNAi plants (GhSWEET12i) possessed similar fiber phenotypes to those of GhMYB212i. Exogenous sucrose supplementation in ovule cultures did not rescue the shorter fiber phenotype of GhMYB212i and GhSWEET12i. This finding supported the idea that the attenuated rate of sucrose transport from the outer seed coat into the fibers is responsible for the retardation of fiber elongation. Current investigations support the idea that GhMYB212 functions as the main regulator of fiber elongation by controlling the expression of GhSWEET12, and therefore it is important to study cell expansion and sugar transportation during seed development.

Genome-wide analysis of CrRLK1L genes and their expression profiling during fiber development in cotton

“…Furthermore, analysis of the cis-elements in the promoter of 22 speci cally expressed genes revealed that NAC, MYB and WRKY transcription factors binding sites were localized in all the promoters. This result indicted that MYB, NAC and WRKY transcription factors might regulate the expression of GhCrRLK1Ls during ber development, which was consistent with the previous reports that MYB transcription factors such as GhMYB109, GhMYB25, GhMYB25-like and GhMYB212 play vital roles in ber development [15,16,18,32]. The functions of NAC and WRKY transcription factors in ber development need further research.…”

“…SiRNA derived from NATs participated in posttranscription gene silencing of GhMML3_A12, which leads to the fuzzless phenotype in N1 mutant [16,17]. Besides these, silencing of GhMYB212 or GhSWEET12 in cotton results in the accumulation of sucrose and glucose in ber, short ber length and decreased lint percentage [18].…”

The pomegranate (Punica granatum L.) draft genome dissects genetic divergence between soft‐ and hard‐seeded cultivars

“…Sucrose also functions as a signal in the regulation of strawberry fruit development and ripening (Jia et al, 2013). Sugar transport during seed development is also required for fibre elongation in cotton (Sun et al, 2018). On the basis of annotations in the 'Tunisia' genome, the PgL0145770 and PgL0145810 genes on chromosome 3 in the soft-seeded population were determined to encode the sucrose transport proteins SUC8-like and SUC6, respectively (Figure 4a).…”

Disequilibrium evolution of Fructose-1,6-bisphosphatase gene family leads to their functional biodiversity in Gossypium species

“…The secondary expansion of epidemic cells is initiated after 7 to 10 DPA, and these cells gradually develop into fuzz that is attached to the surface of a seed [55][56][57]. Factors that influence the initiation, differentiation, and development of fibers include phytohormones, such as IAA and GA, and brassinolactone, as well as transcription factors [58][59][60][61]. The arrangement of cellulose deposition plays an important role in the formation of fiber strength and fineness [62,63].…”