Sucrose non-ferment 1 related protein kinase 2 (SnRK2) genes could mediate the stress responses in potato (Solanum tuberosum L.)

Jiangping Bai,Awais Khan,Hongyu Yang,Aqi Fan,Siyan Liu,Juan Mao,Huijuan Gao,Junlian Zhang,Di Wang,Jinlin Zhang

doi:10.1186/s12863-017-0506-6

Abstract

BackgroundThe SnRKs (sucrose non-fermenting 1 related protein kinase) are a gene family coding for Ser/Thr protein kinases and play important roles in linking the tolerance and metabolic responses of plants to abiotic stresses. To date, no genome-wide characterization of the sucrose non-ferment 1 related protein kinase 2 (SnRK2) subfamily has been conducted in potato (Solanum tuberosum L.).ResultsIn this study, eight StSnRK2 genes (StSnRK2.1- StSnRK2.8) were identified in the genome of the potato (Solanum tuberosum L.) cultivar ‘Longshu 3’, with similar characteristics to SnRK2 from other plant species in gene structure, motif distribution and secondary structures. The C-terminal regions were highly divergent among StSnRK2s, while they all carried the similar Ser/Thr protein kinase domain. The fluorescence of GFP fused with StSnRK2.1, StSnRK2.2, StSnRK2.6, StSnRK2.7 and StSnRK2.8 was detected in the nucleus and cytoplasm of onion epidermal cells with StSnRK2.3 and StSnRK2.4 mainly associated to the nucleus while StSnRK2.5 to subcellular organelles. Expression level analysis by qRT-PCR showed that StSnRK2.1, 2.2, 2.5 and 2.6 were more than 1 fold higher in the root than in the leaf, tuber and stem tissues. The expressions of StSnRK2.3, 2.7, and 2.8 were at least 1.5 folds higher in the leaf and stem than in the root, but lower in the tuber. The expression of StSnRK2.4 was also significantly (P < 0.05) higher in leaf, stem, and tuber than in the root. From the perspective of the relative expressions of StSnRK2 genes in potato, ABA treatment had a different effect from NaCl and PEG treatments.ConclusionIn the present study, we identified and characterized eight SnRK2s in the potato genome. The eight StSnRK2s exhibit similar gene structure and secondary structures in potato to the SnRK2s found in other plant species. The relative expression of eight genes varied among various tissues (roots, leaves, tubers, and stems) and abiotic stresses (ABA, NaCl and PEG-6000) with the prolongation of treatments. This study provides valuable information for the future functional dissection of potato SnRK2 genes in stress signal transduction, plant growth and development.

Highlights

The Sucrose non-ferment related protein kinase (SnRK) are a gene family coding for Ser/Thr protein kinases and play important roles in linking the tolerance and metabolic responses of plants to abiotic stresses
The fluorescence of GFP fused with StSnRK2.1, StSnRK2.2, StSnRK2.6, StSnRK2.7, and StSnRK2.8 was detected in the nucleus and cytoplasm of onion epidermal cells
StSnRK2.3 and StSnRK2.4 are mainly associated to the nucleus, while StSnRK2.5 seems to be associated to subcellular organelles

Summary

Introduction

The SnRKs (sucrose non-fermenting 1 related protein kinase) are a gene family coding for Ser/Thr protein kinases and play important roles in linking the tolerance and metabolic responses of plants to abiotic stresses. No genome-wide characterization of the sucrose non-ferment 1 related protein kinase 2 (SnRK2) subfamily has been conducted in potato (Solanum tuberosum L.). The SnRKs (sucrose non-fermenting 1 related protein kinase) are a gene family coding for Ser/Thr protein kinases and play important roles in linking abiotic stress tolerance and the metabolic responses of plants [8,9,10]. SnRK1 plays an important role in regulating carbon metabolism and energy conversion in plants [11, 12], while SnRK3 is involved in plant development, calcium-responsive regulatory loop and abscisic acid (ABA) sensitivity. SnRK2 members are the major players in plant responses to osmotic stresses [13,14,15,16], ABA dependent and independent stomatal closure-opening [17], fruit development [18], seed dormancy [19] and germination [20, 21]

Methods

Results

Conclusion