The Physiological Functions of Universal Stress Proteins and Their Molecular Mechanism to Protect Plants From Environmental Stresses.

Yong Hun Chi,Dae-Jin Yun,Min Gab Kim,Sung Sun Koo,Hun Taek Oh,Su Bin Bae,Sang Yeol Lee,Eun Seon Lee,Joung Hun Park,Woe-Yeon Kim,Seong Dong Wi,Ho Byoung Chae,Kieu Anh Thi Phan,Seol Ki Paeng,Chang Ho Kang

doi:10.3389/fpls.2019.00750

Yong Hun Chi, Dae-Jin Yun + Show 13 more

Open Access

https://doi.org/10.3389/fpls.2019.00750

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Abstract

Since the original discovery of a Universal Stress Protein (USP) in Escherichia coli, a number of USPs have been identified from diverse sources including archaea, bacteria, plants, and metazoans. As their name implies, these proteins participate in a broad range of cellular responses to biotic and abiotic stresses. Their physiological functions are associated with ion scavenging, hypoxia responses, cellular mobility, and regulation of cell growth and development. Consistent with their roles in resistance to multiple stresses, USPs show a wide range of structural diversity that results from the diverse range of other functional motifs fused with the USP domain. As well as providing structural diversity, these catalytic motifs are responsible for the diverse biochemical properties of USPs and enable them to act in a number of cellular signaling transducers and metabolic regulators. Despite the importance of USP function in many organisms, the molecular mechanisms by which USPs protect cells and provide stress resistance remain largely unknown. This review addresses the diverse roles of USPs in plants and how the proteins enable plants to resist against multiple stresses in ever-changing environment. Bioinformatic tools used for the collection of a set of USPs from various plant species provide more than 2,100 USPs and their functional diversity in plant physiology. Data from previous studies are used to understand how the biochemical activity of plant USPs modulates biotic and abiotic stress signaling. As USPs interact with the redox protein, thioredoxin, in Arabidopsis and reactive oxygen species (ROS) regulates the activity of USPs, the involvement of USPs in redox-mediated defense signaling is also considered. Finally, this review discusses the biotechnological application of USPs in an agricultural context by considering the development of novel stress-resistant crops through manipulating the expression of USP genes.

Highlights

Plants as sessile organisms are persistently confronted with detrimental factors that are arisen from ever-changing environment
E. coli Universal Stress Protein (USP) belonging to each subclass takes its own specific function in particular environmental stress, as shown in Figure 2A (Kvint et al, 2003; Nachin et al, 2005); USPA and USPD in Class I play their roles in the resistance against oxidative stress and iron scavenging, but USPF and USPG protein in Class II partly participate in the protection of bacterial cells from the same oxidative stress
Transcript level of SlRd2 mRNA, another USP gene in tomato (Solanum lycopersicum), is critically enhanced by the treatment of salt and LiCl, suggesting that the physiological function of SIRd2 might be involved in salt and osmotic stress tolerance in plants (Gutierrez-Beltran et al, 2017)

Summary

Introduction

Plants as sessile organisms are persistently confronted with detrimental factors that are arisen from ever-changing environment. E. coli USP belonging to each subclass takes its own specific function in particular environmental stress, as shown in Figure 2A (Kvint et al, 2003; Nachin et al, 2005); USPA and USPD in Class I play their roles in the resistance against oxidative stress and iron scavenging, but USPF and USPG protein in Class II partly participate in the protection of bacterial cells from the same oxidative stress.

Results

Conclusion