Cloning and abiotic stress expression analysis of galactose-binding lectin (GBL) gene from mulberry and its prokaryotic expression in E. coli

ABSTRACT

Galactose-binding lectins (GBLs) are a subdivision of jacalin-related lectins and known to perform an essential role in plant protective mechanisms against plant pathogens, fungi, and viruses. A cDNA sequence encoding GBL was cloned and the gene has an open reading frame (ORF) of 657 bp, encoding a protein of 219 amino acids. The protein is predicted to have a molecular weight and isoelectric point (pI) of 23.76 kDa and 6.29, respectively. GBL has a jacalin-type lectin domain and fits into the JRL superfamily. The evolutionary relationship of GBL revealed that the GBL from Morus multicaulis was firmly related to that of Morus rotundibila, Morus alba, Morus notabilis, Artocarpus integer, Artocarpus nitidus and Champedak (cgb). qRT-PCR analysis showed that the gene was expressed in all the tissues tested, leaf, and bud displaying the highest transcript levels. There was a general decrease in the mRNA transcript level under cold and salt stress as compared to the mRNA transcript level of the control. SDS-PAGE and western blot results showed that His-tagged fusion GBL protein was positively expressed in E. coli. In total, our findings disclosed the molecular basis for the signal transduction mechanisms when abiotic stress is induced in a mulberry tree.

KEYWORDS:

• Mulberry
• galactose-binding lectin
• characterisation
• expression analysis
• prokaryotic expression

Acknowledgments

This work was supported by Sericulture Industry Technology in China Agriculture Research System (CARS-18-ZJ0207); Guangxi innovation driven development project (AA19182012-2); Open Program of Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture (KL201906); the Crop Germplasm Resources Protection Project of the Agriculture Ministry (111721301354052026); and National Infrastructure for Crop Germplasm Resources (NICGR-43).

Contribution

Conceived and designed the experiments: LY HF ZJ ZW. Performed the experiments: LY HF AA JAC LY DQ GP ZD. Analyzed the data: LY HF FR. Provided mulberry samples LL LQ. Wrote the manuscript: LY HF.

Disclosure statement

The authors declare that they have no conflict of interest.

Additional information

Funding

This work was supported by the National Infrastructure for Crop Germplasm Resources [NICGR-43]; Guangxi innovation driven development project [AA19182012-2]; Sericulture Industry Technology in China Agriculture Research System [CARS-18-ZJ0207]; the Crop Germplasm Resources Protection Project of the Agriculture Ministry [111721301354052026]; Open Program of Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture [KL201906].