SiFBA5, a cold-responsive factor from Saussurea involucrata promotes cold resilience and biomass increase in transgenic tomato plants under cold stress

Jianqiang Mu,Yajuan Fu,Aiying Wang,Jianbo Zhu,Bucang Liu,Yao Zhang,Yuxia Li

doi:10.1186/s12870-021-02851-8

Jianqiang Mu, Yajuan Fu + Show 5 more

Open Access

https://doi.org/10.1186/s12870-021-02851-8

Copy DOI

Abstract

BackgroundSaussurea involucrata survives in extreme arctic conditions and is very cold-resistant. This species grows in rocky, mountainous areas with elevations of 2400–4100 m, which are snow-covered year-round and are subject to freezing temperatures. S. involucrata’s ability to survive in an extreme low-temperature environment suggests that it has particularly high photosynthetic efficiency, providing a magnificent model, and rich gene pool, for the analysis of plant cold stress response. Fructose-1, 6-bisphosphate aldolase (FBA) is a key enzyme in the photosynthesis process and also mediates the conversion of fructose 1, 6-bisphosphate (FBP) into dihydroxyacetone phosphate (DHAP) and glycerol triphosphate (GAP) during glycolysis and gluconeogenesis. The molecular mechanisms underlying S. involucrata’s cold tolerance are still unclear; therefore, our work aims to investigate the role of FBA in plant cold-stress response.ResultsIn this study, we identified a cold-responsive gene, SiFBA5, based on a preliminary low-temperature, genome-wide transcriptional profiling of S. involucrata. Expression analysis indicated that cold temperatures rapidly induced transcriptional expression of SiFBA5, suggesting that SiFBA5 participates in the initial stress response. Subcellular localization analysis revealed that SiFBA5 is localized to the chloroplast. Transgenic tomato plants that overexpressed SiFBA5 were generated using a CaMV 35S promoter. Phenotypic observation suggested that the transgenic plants displayed increased cold tolerance and photosynthetic efficiency in comparison with wild-type plants.ConclusionCold stress has a detrimental impact on crop yield. Our results demonstrated that SiFBA5 positively regulates plant response to cold stress, which is of great significance for increasing crop yield under cold stress conditions.

Highlights

Saussurea involucrata survives in extreme arctic conditions and is very cold-resistant
Isolation of siFBA5 from S. involucrata SiFBA5 cDNA was identified from transcriptome sequencing of S. involucrata
Sequencing analysis revealed that the open reading frame (ORF) of SiFBA5 cDNA (1179 bp) encodes a 392-amino-acid protein, with a molecular mass of 42.57 kDa and isoelectric point of 8.84 (Figure S1-S2)

Summary

Introduction

Saussurea involucrata survives in extreme arctic conditions and is very cold-resistant. The Calvin cycle is a critical part of photosynthetic carbon fixation, providing essential compounds for plant survival [1, 2] This process is associated with a variety of catalytic reactions and divided into three distinct phases: carbon fixation, reduction, and regeneration of the starting molecule [3]. Rubisco is not always the most active enzyme during the Calvin cycle, other enzymes probably exert greater control over carbon flow during photosynthesis, sedoheptulose-1, 7-bisphosphatase (SBPase), transketolase (TK), and fructose-1,6-bisphosphate aldolase (FBA). These enzymes are candidates for study in efforts to increase photosynthetic carbon fixation [3, 5]

Methods

Results

Discussion

Conclusion