GhCFE1A, a dynamic linker between the ER network and actin cytoskeleton, plays an important role in cotton fibre cell initiation and elongation

Abstract

Fibre cell initiation and elongation is critical for cotton fibre development. However, little is known about the regulation of initiation and elongation during fibre cell development. Here, the regulatory role of a novel protein GhCFE1A was uncovered. GhCFE1A is preferentially expressed at initiation and rapid elongation stages during fibre development; in addition, much higher expression of GhCFE1A was detected at the fibre initiation stage in fibreless cotton mutants than in the fibre-bearing TM-1 wild-type. Importantly, overexpression of GhCFE1A in cotton not only delayed fibre cell elongation but also significantly reduced the density of lint and fuzz fibre initials and stem trichomes. Yeast two-hybrid assay showed that GhCFE1A interacted with several actin proteins, and the interaction was further confirmed by co-sedimentation assay. Interestingly, a subcellular localization assay showed that GhCFE1A resided on the cortical endoplasmic reticulum (ER) network and co-localized with actin cables. Moreover, the density of F-actin filaments was shown to be reduced in GhCFE1A-overexpressing fibres at the rapid elongation stage compared with the wild-type control. Taken together, the results demonstrate that GhCFE1A probably functions as a dynamic linker between the actin cytoskeleton and the ER network, and plays an important role in fibre cell initiation and elongation during cotton fibre development.

A Cotton Annexin Affects Fiber Elongation and Secondary Cell Wall Biosynthesis Associated with Ca2+ Influx, ROS Homeostasis, and Actin Filament Reorganization

“…Silencing of GhACT1 inhibits fiber cell elongation by reducing the amount of F-actin (Li et al, 2005), similar to that reported for root hair growth in Arabidopsis (Arabidopsis thaliana; Gilliland et al, 2003). Subsequently, WLIM1a and GhCFE1A were shown to function in fiber elongation by acting as an actin bundler and a dynamic linker between the endoplasmic reticulum network and the actin cytoskeleton, respectively (Han et al, 2013;Lv et al, 2015). Unfortunately, although these factors were considered to participate in fiber elongation, their precise contribution to the dynamic behavior of fiber elongation remains poorly characterized.…”

A Gly65Val substitution in an actin, GhACT_LI1, disrupts cell polarity and F‐actin organization resulting in dwarf, lintless cotton plants

“…Interestingly, the profilin family of actin‐binding proteins was shown to have been up‐regulated following independent domestication of different cotton species, underscoring the importance of the cytoskeleton in the production of the commercially attractive, highly elongated cotton fiber (Bao et al ., ). Recently, additional actin‐interacting proteins have been characterized in cotton, and shown to play roles in cotton fiber cell elongation (Preuss et al ., ; Li et al ., ; Wang et al ., ; Huang et al ., ; Lv et al ., ).…”

GhHUB2, a ubiquitin ligase, is involved in cotton fiber development via the ubiquitin–26S proteasome pathway

“…Substantial progress has been made in identifying the regulators involved in fiber elongation and SCW formation ( Ruan et al , 2003 ; Li et al , 2005 , 2016 ; Han et al , 2013 ; Xu et al , 2013 ; Shan et al , 2014 ; Lv et al , 2015 ; Zhang et al , 2018 ). A recent study examined the SCWs from different cotton tissues and identified several genes specially expressed in fibers, including two AtKNAT7 homologs that were expressed during the fiber transition and SCW deposition stages ( MacMillan et al , 2017 ).…”