Identification and functional analysis of proteins in response to light intensity, temperature and water potential in Brassica rapa hypocotyl

Abstract

Hypocotyl elongation is an early event in plant growth and development and is sensitive to fluctuations in light, temperature, water potential and nutrients. Most research on hypocotyl elongation has focused on the regulatory mechanism of a single environment factor. However, information about combined effects of multi‐environment factors remains unavailable, and overlapping sites of the environmental factors signaling pathways in the regulation of hypocotyl elongation remain unclear. To identify how cross‐talks among light intensity, temperature and water potential regulate hypocotyl elongation in Brassica rapa L. ssp. chinesis, a comprehensive isobaric tag for relative and absolute quantitation‐based proteomic approach was adopted. In total, 7259 proteins were quantified, and 378 differentially expressed proteins (DEPs) were responsive to all three environmental factors. The DEPs were involved in a variety of biochemical processes, including signal transduction, cytoskeletal organization, carbohydrate metabolism, cell wall organization, protein modification and transport. The DEPs did not function in isolation, but acted in a large and complex interaction network to affect hypocotyl elongation. Among the DEPs, phyB was outstanding for its significant fold change in quantity and complex interaction networks with other proteins. In addition, changes of sensitivity to environmental factors in phyB‐9 suggested a key role in the regulation of hypocotyl elongation. Overall, the data presented in this study show a profile of proteins interaction network in response to light intensity, temperature and water potential and provides molecular basis of hypocotyl elongation in B. rapa.

The combined effects of light intensity, temperature, and water potential on wall deposition in regulating hypocotyl elongation of Brassica rapa

“…As the receptor of multiple environmental factors, phytochrome B (phyB) played a critical role both in regulating cell elongation in hypocotyl growth and cell division during stomatal development that accounted for the increase in cell layers in the epidermis of B. rapa hypocotyl (Fig. 2) (Casson et al, 2009;Wang & Shang, 2019). Moreover, low light, high temperature, and high water potential significantly promoted cell elongation in hypocotyl by increasing auxin content, which is primarily biosynthesized by YUCCA8/9 in dicotyledonous plants (Sun et al, 2012;Zhao, 2010).…”

“…As the emerging hub of environmental signaling pathways in regulating hypocotyl elongation, the protein abundance and activity state of phyB are regulated by light intensity, temperature, and water potential. Casal & Questa (2018), Legris et al (2017) and Wang & Shang (2019). In addition, phyB also regulated hypocotyl elongation by regulating the signaling of hormones, such as IAA and BR.…”

Peer Review #2 of "The combined effects of light intensity, temperature, and water potential on wall deposition in regulating hypocotyl elongation of Brassica rapa (v0.2)"

“…As the receptor of multiple environmental factors, phytochrome B (phyB) played a critical role both in regulating cell elongation in hypocotyl growth and cell division during stomatal development that accounted for the increase in cell layers in the epidermis of B. rapa hypocotyl (Fig. 2) (Casson et al, 2009;Wang & Shang, 2018). Moreover, low light, high temperature, and high water potential significantly promoted cell elongation in hypocotyl by increasing auxin content, which is primarily biosynthesized by YUCCA8/9 in dicotyledonous plants (Sun et al, 2012;Zhao, 2010).…”

“…As the emerging hub of environmental signaling pathways in regulating hypocotyl elongation, the protein abundance and activity state of phyB are regulated by light intensity, temperature, and water potential. (Casal & Questa, 2018;Legris et al, 2017;Wang & Shang, 2018). In addition, phyB also regulated hypocotyl elongation by regulating the signaling of hormones, such as IAA and BR.…”