cDNA cloning and expression analysis of a mannose-binding lectin from Pinellia pedatisecta

Area of Science:

• Plant biochemistry
• Molecular biology
• Genetics

Background:

• Pinellia pedatisecta agglutinin (PPA) is a basic protein found in P. pedatisecta tubers.
• PPA is a 40 kDa hetero-tetramer protein composed of two polypeptide chains A and two polypeptide chains B.

Purpose of the Study:

• To clone the full-length cDNA of PPA from P. pedatisecta.
• To analyze the PPA precursor's structure, including mannose-binding sites and conserved domains.
• To investigate the PPA gene's family size, expression patterns, and potential applications.

Main Methods:

• SMART RACE-PCR technology was used to clone the full-length PPA cDNA.
• Southern blot analysis was performed to determine the gene copy number.
• Expression pattern analysis was conducted across various P. pedatisecta tissues.

Main Results:

• The cloned PPA cDNA was 1146 bp, containing a 771 bp ORF encoding a 256-amino acid lectin precursor with a signal peptide.
• The precursor contained three mannose-binding sites and two conserved domains (PPA-DOM 1 and PPA-DOM 2).
• Southern blot indicated PPA is a multi-copy gene family, with high expression in spadix, spathe, and tuber.

Conclusions:

• Cloning the PPA gene provides a foundation for studying its structure, expression, and regulation.
• The PPA gene holds potential for future applications in pest and fungal disease control through gene transfer into plants.