Comprehensive Analysis of StSRO Gene Family and Its Expression in Response to Different Abiotic Stresses in Potato

Abstract

As a highly conserved family of plant-specific proteins, SIMILAR-TO-RCD-ONE (SROs) play an essential role in plant growth, development and response to abiotic stresses. In this study, six StSRO genes were identified by searching the PARP, RST and WWE domains based on the genome-wide data of potato database DM v6.1, and they were named StSRO1–6 according to their locations on chromosomes. StSRO genes were comprehensively analyzed using bioinformatics methods. The results showed that six StSRO genes were irregularly distributed on five chromosomes. Phylogenetic analysis showed that 30 SRO genes of four species were distributed in three groups, while StSRO genes were distributed in groups II and III. The promoter sequence of StSRO genes contained many cis-acting elements related to hormones and stress responses. In addition, the expression level of StSRO genes in different tissues of doubled monoploid (DM) potato, as well as under salt, drought stresses and hormone treatments, was analyzed by RNA-seq data from the online database and quantitative real-time polymerase chain reaction (qRT-PCR) analysis. Furthermore, the expression level of StSRO genes was analyzed by transcriptome analysis under mild, moderate and severe salt stress. It was concluded that StSRO genes could respond to different abiotic conditions, but their expression level was significantly different. This study lays a foundation for further studies on the biological functions of the StSRO gene family.

Genome-wide identification of SIMILAR to RCD ONE (SRO) gene family in rapeseed ( Brassica napus L.) reveals their role in drought stress response

“…Phylogenetic analyses with different plant SROs revealed that the 86 SRO members of the abovementioned six Brassica species could be categorized into four subgroups, and members within the same subgroup presented similar gene structures and conserved motif compositions. This phenomenon has also been found in other plant SROs studies as well as in other gene family identifications, 18 , 19 , 41 , 42 further demonstrating their close evolutionary relationship. In addition, our evolutionary tree results showed that, with the exception of individual members, the SROs of monocotyledonous and dicotyledonous plants were in separate subgroups.…”

“…However, although different members presented diverse response expression patterns, none of them showed regular changes. This phenomenon has been found in studies of other plant SROs , such as those of rice, 6 maize, 14 poplar, 22 tea plant, 21 potato 18 and tomato, 16 and has also been presented in the analysis of other gene families. This might be related to the different regulatory mechanisms they were subjected to during the different treatment periods.…”

“… 16 In potato, rice and poplar, the expression of all members of the SRO family was induced upon ABA treatment. 6 , 18 , 22 In the MeJA treatment group, BnaSRO1 , BnaSRO4 , BnaSRO6 , BnaSRO10 , BnaSRO11 , and BnaSRO19 were significantly up-regulated in the early treatment group, whereas BnaSRO2 , BnaSRO7 , BnaSRO8 , BnaSRO9 , BnaSRO12 , BnaSRO13 , BnaSRO14 , BnaSRO15 , and BnaSRO16 were up-regulated in the later treatment group. In tomato, the SolySRO1 gene was significantly up-regulated starting 6 h after MeSA treatment and consistently continued for 24 h, while SolySRO3 and SolySRO4 were significantly up-regulated only at 12 h 16 .…”

“…For drought treatment, most studies have used PEG treatment to simulate drought. 16 , 18 , 21 , 22 In this study, we used the direct drought form of the water deficit treatment to simulate real-world conditions. We found that the expression of BnaSRO1 , BnaSRO4 , BnaSRO10 , BnaSRO11 , and BnaSRO15 peaked 3 d after drought treatment; that of BnaSRO6 , BnaSRO9 , BnaSRO12 , and BnaSRO16 peaked 5 d after drought treatment; and that of BnaSRO13 peaked 7 d after drought treatment.…”

“…As an increasing number of plant genomes have been sequenced, the SRO gene family has been consecutively identified in different plants, such as rice, 6 maize, 14 wheat, 15 tomato, 16 cotton, 17 potato, 18 sesame, 19 banana, 20 tea plant 21 and poplar, 22 and the understanding of their functions is expanding. In rice, the five SRO genes can respond to a multitude of abiotic stresses, 23 in which OsSRO1c is directly regulated by the transcription factor gene SNAC1 to enhance rice drought and oxidative stress tolerance.…”