Heterologous Overexpression of Sorghum SbSnRK2.1 Enhances the Resistance to Salt Stress in Arabidopsis

doi:10.13560/j.cnki.biotech.bull.1985.2025-0114

Abstract

Abstract:

Objective This study aims to identify SNF1-RELATED KINASE 2 (SnRK2) genes from the sorghum genome that regulate plant responses to salt stress, thereby providing a theoretical basis for investigating salt tolerance mechanisms in sorghum. Method Bioinformatics techniques were employed to identify and analyze the sequence characteristics of sorghum SnRK2 gene family members (SbSnRK2s). Quantitative PCR was used to examine the dynamic expression patterns of SbSnRK2s within 12 h of salt stress treatment. Genes showing significant upregulation under salt stress were heterologously overexpressed in Arabidopsis thaliana to evaluate changes in salt stress tolerance. Result Eleven SbSnRK2s genes were identified in the sorghum genome, unevenly distributed across seven chromosomes. Phylogenetic analysis of protein sequences revealed close evolutionary relationships between SbSnRK2s and SnRK2 genes from maize, another C₄ plant. Promoter analysis identified regulatory elements responsive to hormones and stress. All 11 SbSnRK2s exhibited upregulated expression under salt stress, with SbSnRK2.1 showing the most pronounced induction (>150-fold increase at 9 h post-treatment). Arabidopsis thaliana heterologously expressing SbSnRK2.1 demonstrated significantly higher survival rates, primary root lengths, and fresh weights compared to wild-type plants under salt stress conditions. Conclusion SbSnRK2.1 demonstrates remarkable upregulation in response to salt treatment, and its heterologous overexpression significantly enhances the tolerance of Arabidopsis thaliana to salt stress, indicating its crucial role in plant responses to salinity stress.

Key words: SnRK2, sorghum, salt resistance, heterologous overexpression, Arabidopsis thaliana

LI Ya-qiong, GESANG La-mao, CHEN Qi-di, YANG Yu-huan, HE Hua-zhuan, ZHAO Yao-fei. Heterologous Overexpression of Sorghum SbSnRK2.1 Enhances the Resistance to Salt Stress in Arabidopsis[J]. Biotechnology Bulletin, 2025, 41(8): 115-123.

Figures/Tables 10

Table 1 Primers used in this study

引物名称 Primer name	序列 Sequence （5′‒3′）
SbSnRK2.1-F	GCCTTCTTACTCAGACCAAT
SbSnRK2.1-R	TCCTTCTCTTCTTCTTCATCC
SbSnRK2.2-F	CGGCTATTCCAAGTCATCT
SbSnRK2.2-R	GCACCAACAACCATTACATA
SbSnRK2.3-F	TCATCAGTTCTACACTCTCAG
SbSnRK2.3-R	ACCGACCAGCATCACATA
SbSnRK2.4-F	AGGACGAGGCAAGGTATT
SbSnRK2.4-R	CAGCAGCGATGACTTAGA
SbSnRK2.5-F	TCAGGCTATGGCTACAGT
SbSnRK2.5-R	CACACTCATCTTCTTCTTCC
SbSnRK2.6-F	CACTCTGCTGGATGGAAG
SbSnRK2.6-R	CAATCTTGCCGTCGTATTC
SbSnRK2.7-F	TTCGCCGTCAAGTTCATC
SbSnRK2.7-R	GCCAGCAGCATATTCCATA
SbSnRK2.8-F	GTGAGAATGAGGCAAGGTT
SbSnRK2.8-F	TGAGAGTGAAGAACAGAAGAC
SbSnRK2.9-R	CATGAGGATCGTTCAGGAG
SbSnRK2.9-F	TGTCGTAGTCGTCTTCTTC
SbSnRK2.10-R	ACTTACTCCGTCCAGTCC
SbSnRK2.10-F	CCATCCTCTTCCTCCTCAT
SbSnRK2.11-R	GGCAAGAAGATTGATGAGAA
SbSnRK2.11-R	TCCACCAGCAGCATATTC

Table 2 Information of SnRK2 genes in sorghum (SbSnRK2s)

基因 Gene	基因ID Gene ID	基因长度 Gene length （bp）	CDS长度 CDS length （bp）
SbSnRK2.1	Sobic.003G370100	5 130	1 086
SbSnRK2.2	Sobic.001G078800	7 044	1 101
SbSnRK2.3	Sobic.001G168400	3 201	1 089
SbSnRK2.4	Sobic.004G173500	5 029	1 095
SbSnRK2.5	Sobic.009G149900	4 945	1 080
SbSnRK2.6	Sobic.008G147000	2 691	1 095
SbSnRK2.7	Sobic.002G379400	4 989	1 020
SbSnRK2.8	Sobic.001G350700	4 525	1 035
SbSnRK2.9	Sobic.006G279100	6 401	1 140
SbSnRK2.10	Sobic.006G083000	5 786	1 134
SbSnRK2.11	Sobic.001G294400	3 307	1 002

Fig. 1 Distribution of SbSnRK2s in the genome of sorghumChromosomal distances are given in Mb

Fig. 2 Gene structure analysis of SbSnRK2sThe yellow part indicates the exon, the black solid line indicates the intron, and the blue part indicates the sequence of the upstream and downstream non-coding regions of the SbSnRK2 genes

Fig. 3 Promoter characteristics analysis of SbSnRK2 genes

Fig. 4 Phylogenetic analysis of SnRK2Sb: Sorghum bicolor; At: Arabidopsis thaliana; Os: Oryza sativa; Zm: Zea mays

Fig. 5 Expression patterns of the SbSnRK2s under salt stressDifferent letters above the bar chart indicate significant differences at P<0.05

Fig. 6 Phenotype (A) and the survival rates (B) of plants overexpressing SbSnRK2.1 under salt stress

Fig. 7 Heterologous overexpression of SbSnRK2.1 promotes the primary root growth of A. thaliana under salt stressA: Growth of primary roots under normal and salt stress conditions, bar = 1 cm. B: Statistics of primary root length. C: Relative root length (ratio of root length under salt stress to average root length under normal growth conditions)

Fig. 8 Variation in fresh weights of heterologously-overexpressed SbSnRK2.1 and wild A. thaliana under salt stress

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