Abstract
High-quality cotton fibre equates to a more comfortable textile. Fibre length is an important index of fibre quality. Hydrogen peroxide (H2O2) acts as a
signalling molecule in the regulation of fibre elongation. Results fromin vitroovule culture suggest
that the alteration of fibre cell
H2O2levels
affects fibredevelopment. Ascorbate peroxidase (APX) is an important reactive oxygen
species (ROS) scavenging enzyme, and we found thatGhAPX1AT/DTencoded one member of the previously unrealized
group of cytosolic APXs (cAPXs) that were preferentially
expressed during the fibre elongationstage. Transgenic cottons with up- and
down-regulation ofGhAPX1AT/DT were
generated to control fibre endogenous
levels of H2O2 Suppression of allcAPX(IAO) resulted
in a 3.5-fold increase in H2O2level in fibres and oxidative stress, which
significantly suppressed fibre elongation. The fibrelength of transgenic lines with over-expression or
specific down-regulation ofGhAPX1AT/DT did
not show any obvious change. However, the fibres in the over-expression lines
exhibited higher tolerance to oxidative stress. Differentially expressed genes
(DEGs) in fibres at 10 days post-anthesis (DPA) of IAO lines identified by
RNA-seq were related to redox homeostasis, signalling pathways, stress responses and
cell wall synthesis, and the DEGs that were up-regulated in IAO lines were also
up-regulated in the 10 DPA and 20 DPA fibres of wild cotton compared with domesticated cotton.
These results suggest that optimal H2O2levels and redox state
regulated by cytosolic APX
are key mechanisms regulating fibre elongation, and dysregulation of the increase in H2O2induces
oxidative stress and results in shorter fibres by initiating secondary cell
wall-related gene expression.
http://www.ncbi.nlm.nih.gov/pubmed/?term=Fibre%20elongation%20requires%20normal%20redox%20homeostasis%20modulated%20by%20cytosolic%20ascorbate%20peroxidase%20in%20%20cotton
pii: erw146. (IF=5.526)
PMID: 27091877.