Genome-Wide Identification and Characterization of CDPK Family Reveal Their Involvements in Growth and Development and Abiotic Stress in Sweet Potato and Its Two Diploid Relatives.

Xu Li,Qingchang Liu,Limeng Zhao,Shaopei Gao,Hong Zhai,Shaozhen He,Ning Zhao,Huan Zhang

doi:10.3390/ijms23063088

Abstract

Calcium-dependent protein kinase (CDPKs) is one of the calcium-sensing proteins in plants. They are likely to play important roles in growth and development and abiotic stress responses. However, these functions have not been explored in sweet potato. In this study, we identified 39 CDPKs in cultivated hexaploid sweet potato (Ipomoea batatas, 2n = 6x = 90), 35 CDPKs in diploid relative Ipomoea trifida (2n = 2x = 30), and 35 CDPKs in Ipomoea triloba (2n = 2x = 30) via genome structure analysis and phylogenetic characterization, respectively. The protein physiological property, chromosome localization, phylogenetic relationship, gene structure, promoter cis-acting regulatory elements, and protein interaction network were systematically investigated to explore the possible roles of homologous CDPKs in the growth and development and abiotic stress responses of sweet potato. The expression profiles of the identified CDPKs in different tissues and treatments revealed tissue specificity and various expression patterns in sweet potato and its two diploid relatives, supporting the difference in the evolutionary trajectories of hexaploid sweet potato. These results are a critical first step in understanding the functions of sweet potato CDPK genes and provide more candidate genes for improving yield and abiotic stress tolerance in cultivated sweet potato.

Highlights

Ca2+ is an important second messenger in plants, and signaling pathways mediated by Ca2+ have been shown to play an important role in plant growth and development in response to abiotic and biotic stresses [1,2]
Sci. 2022, 23, 3088 total of 39, 35, and 35 Calcium-dependent protein kinase (CDPKs) were identified in I. batatas, I. trifida, and I. triloba, respectively
The amino acid lengths of IbCDPKs were distributed from 351 aa (IbCDPK25.4) to 1170 aa (IbCDPK16), the molecular weight (MW) ranged from 38.732 kDa to 130.824 kDa, and the isoelectric point varied from 4.75 (IbCDPK25.4) to 9.28 (IbCDPK28)

Summary

Introduction

Ca2+ is an important second messenger in plants, and signaling pathways mediated by Ca2+ have been shown to play an important role in plant growth and development in response to abiotic and biotic stresses [1,2]. There are three families of calcium-sensing proteins in plants, including calmodulin (CaM) and calmodulin-like protein (CaML), calciumdependent protein kinase (CDPK), and calcineurin B-like proteins (CBLs)/CBL-interacting proteins (CIPK) [3–7]. Among these sensors, CDPKs are Ser/Thr protein kinases, serving as special sensors as they can directly convert upstream Ca2+ signals into downstream protein phosphorylation events [8]. Genome-wide analysis led to the identification of CDPK genes in various plant species. There are 34 genes in Arabidopsis thaliana [3], 31 in rice (Oryza sativa) [9], 20 in wheat (Triticum aestivum) [10], 35 in maize (Zea mays) [11], 29 in poplar (Populus trichocarpa) [12], and 19 in grape (Vitis spp.) [13]

Methods

Results

Discussion

Conclusion