Abstract
BackgroundCell elongation and expansion are significant contributors to plant growth and morphogenesis, and are often regulated by environmental cues and endogenous hormones. Auxin is one of the most important phytohormones involved in the regulation of plant growth and development and plays key roles in plant cell expansion and elongation. Cotton fiber cells are a model system for studying cell elongation due to their large size. Cotton is also the world’s most utilized crop for the production of natural fibers for textile and garment industries, and targeted expression of the IAA biosynthetic gene iaaM increased cotton fiber initiation. Polar auxin transport, mediated by PIN and AUX/LAX proteins, plays a central role in the control of auxin distribution. However, very limited information about PIN-FORMED (PIN) efflux carriers in cotton is known.ResultsIn this study, 17 PIN-FORMED (PIN) efflux carrier family members were identified in the Gossypium hirsutum (G. hirsutum) genome. We found that PIN1–3 and PIN2 genes originated from the At subgenome were highly expressed in roots. Additionally, evaluation of gene expression patterns indicated that PIN genes are differentially induced by various abiotic stresses. Furthermore, we found that the majority of cotton PIN genes contained auxin (AuxREs) and salicylic acid (SA) responsive elements in their promoter regions were significantly up-regulated by exogenous hormone treatment.ConclusionsOur results provide a comprehensive analysis of the PIN gene family in G. hirsutum, including phylogenetic relationships, chromosomal locations, and gene expression and gene duplication analyses. This study sheds light on the precise roles of PIN genes in cotton root development and in adaption to stress responses.
Highlights
Cell elongation and expansion are significant contributors to plant growth and morphogenesis, and are often regulated by environmental cues and endogenous hormones
The results showed that the majority of cotton PIN genes contained auxin response elements (AuxREs) and salicylic acid (SA) responsive elements in their promoter regions, which were significantly up-regulated by exogenous hormone treatment
Our results showed that 6 out of 8 highly expressed genes possessed at Discussion In this work, 17 PIN genes were identified in G. hirsutum, including 8 that originated from the At subgenome and 9 from the Dt subgenome (Additional file 2: Table S1)
Summary
Cell elongation and expansion are significant contributors to plant growth and morphogenesis, and are often regulated by environmental cues and endogenous hormones. Auxin is one of the most important phytohormones involved in the regulation of plant growth and development and plays key roles in plant cell expansion and elongation. The plant phytohormone auxin (indole-3-acetic acid, IAA) plays an essential role in plant morphogenesis, organogenesis, apical dominance, embryo formation, vascular differentiation, and light and gravity perception [1, 2]. Two critical pathways, including auxin transport and auxin signaling, are vital for plant development, playing a major role in both phototropism and gravitropism. Auxin efflux has been observed in specific tissues at different developmental stages, and plays a role in lateral organ initiation, root gravitropism, and root hair formation [7,8,9].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
