Genome-Wide Analysis of OPR Family Genes in Cotton Identified a Role for GhOPR9 in Verticillium dahliae Resistance

Abstract

The 12-oxo-phytodienoic acid reductases (OPRs) have been proven to play a major role in plant development and growth. Although the classification and functions of OPRs have been well understood in Arabidopsis, tomato, rice, maize, and wheat, the information of OPR genes in cotton genome and their responses to biotic and abiotic stresses have not been reported. In this study, we found 10 and 9 OPR genes in Gossypium hirsutum and Gossypium barbadense, respectively. They were classified into three groups, based on the similar gene structure and conserved protein motifs. These OPR genes just located on chromosome 01, chromosome 05, and chromosome 06. In addition, the whole genome duplication (WGD) or segmental duplication events contributed to the evolution of the OPR gene family. The analyses of cis-acting regulatory elements of GhOPRs showed that the functions of OPR genes in cotton might be related to growth, development, hormone, and stresses. Expression patterns showed that GhOPRs were upregulated under salt treatment and repressed by polyethylene glycol 6000 (PEG6000). The expression patterns of GhOPRs were different in leaf, root, and stem under V. dahliae infection. GhOPR9 showed a higher expression level than other OPR genes in cotton root. The virus-induced gene silencing (VIGS) analysis suggested that knockdown of GhOPR9 could increase the susceptibility of cotton to V. dahliae infection. Furthermore, GhOPR9 also modulated the expressions of jasmonic acid (JA) pathway-regulated genes under the V. dahliae infection. Overall, our results provided the evolution and potential functions of the OPR genes in cotton. These findings suggested that GhOPR9 might play an important role in cotton resistance to V. dahliae.

Genome-Wide Analysis of Ribosomal Protein GhRPS6 and Its Role in Cotton Verticillium Wilt Resistance

“…In order to explore the role of GhRPS6 in cotton resistance to V. dahliae , GhRPS6 silenced plants were constructed by Virus-induced gene silencing (VIGS), which uses the modified viral genome to knock out the target gene in a moment, and has been widely used to decipher the function of plant genes [ 32 , 33 , 34 ]. To further verify the feasibility of this method, GhPDS was selected as the visible gene marker, Agrobacteria -GV3101 containing PYL -GhPDS plasmid was injected into cotton cotyledon at 10 days of age, and the albino phenotype appeared 2 weeks later ( Figure 2 a).…”

“…Proteomic data for cotton and Arabidopsis were obtained from CottonFGD ( (accessed on 1 December 2020)) and TAIR10 ( (accessed on 1 December 2020)), respectively. Multisequence alignment of all RPS6 proteins was performed using ClustalX with default parameters [ 32 ]. A phylogenetic tree of the inferred RPS6 amino acid sequence was constructed using a neighbor-joining algorithm with default parameters.…”

“…The MEME program was used to identify the conserved domain in GhRPS6 protein [ 56 ]. MCScanX was used to identify genome collinearity and tandem repeats under default parameters, and Circosv.0.69 was used to show collinearity [ 32 ].…”

The OPR gene family in watermelon: Genome‐wide identification and expression profiling under hormone treatments and root‐knot nematode infection

“…The tea plant ( Camellia sinensis ) CsOPR3 gene was also found to be involved in JA biosynthesis, and its expression was induced by wounding and herbivore infestation (Xin et al 2017). The cotton GhOPR genes were differentially expressed in response to polyethylene glycol stress, salt stress and Verticillium dahliae infection, and knockdown of GhOPR9 by virus‐induced gene silencing (VIGS) could increase susceptibility of cotton to V. dahliae infection by regulating transcripts of JA‐regulated defence genes (Liu et al 2020). These findings indicate that plant OPR genes play key roles in regulating several development processes and stress resistance.…”

“…Plant OPRs are encoded by a multigene family that has been identified in many plants. Previous reports have identified three OPR genes in Arabidopsis (Schaller et al 2000; Biesen & Weiler 1999; Stintzi & Browse 2000), eight genes in maize (Zhang et al 2005), 13 genes in rice (Li et al 2011), 48 genes in wheat (Mou et al 2019) and ten and nine genes in Gossypium hirsutum and G. barbadense , respectively (Liu et al 2020). According to previous phylogenetic analyses of six major green plants, the OPR genes can be classified into two subfamilies in dicots and five subfamilies in monocots (Li et al 2009).…”