Abstract
Biomass production in plant is directly related to the amount of intercepted solar radiation by the canopy and available water to the plant. Growth and development of leaves, especially under drought condition, is therefore major determinant of crop productivity. Xyloglucan endotransglucosylase (XET) plays important role in growth and development of plants. XETs are a family of enzymes that mediate construction and restructuring of xyloglucan cross-links, thereby controlling the mechanical properties of cell wall. We cloned complete cDNA of an XET from pearl millet (Pennisetum glaucum L.) and characterized it using in silico comparative genomics and activity assays. The cloned cDNA was 1266 bp in length, encoding a protein with 291 amino acids having signal peptide targeting it to the cell wall. The protein showed xyloglucan endotransglucosylase activity but no hydrolytic activity, therefore, named as PgXET1 as per the convention. The comparative genomics revealed that the functional sites of the enzyme (XET) were highly conserved. Evolutionary studies using phylogenetic tree indicated its grouping with XETs from maize (with >95% bootstrap support), barley, rice, etc. This is the first report on cloning and characterization of an XET (PgXET1) from pearl millet, an important dual-purpose crop. Key words: Xyloglucan endotransglucosylase, Pennisetum glaucum, pearl millet, primary cell wall, cell expansion, drought tolerance.
Highlights
Plant cells are enclosed by cell walls that define shape and size of cells and mediate cell-to-cell contact
We report, cloning and characterization of complementary deoxyribonucleic acid (cDNA) for an Xyloglucan endotransglucosylase (XET) enzyme in pearl millet (P. glaucum) and studying its evolutionary relationship with known XETs from other species
CDNA encoding a putative XET was cloned from leaf tissues of P. glaucum combining RT-PCR, 5’-rapid amplification of cDNA ends (RACE) and 3’-RACE techniques
Summary
Plant cells are enclosed by cell walls that define shape and size of cells and mediate cell-to-cell contact. The primary cell walls of grasses have different chemical composition when compared with other flowering plants They vary in complex glycans, nature of gel matrix and the types of aromatic substances and structural proteins. The cell wall contains numerous enzymes which can hydrolyze various components of wall matrix This activity is important for wall extension, wall loosening, in defense mechanism, signaling and polysaccharide breakdown to provide energy. A class of enzymes known as xyloglucan endotransglucosylases (XETs) has the potential to enzymatically modify wall components Their biochemical activity has been defined (Campbell and Braam, 1999), the physiological roles remain undefined. Since XET activity is directly related to the growth of plant and elongation of the organs, XET genes are important candidate which may be deployed for engineering forage crops to improve plant growth and cell wall components (Burstin, 2000). We report, cloning and characterization of cDNA for an XET enzyme in pearl millet (P. glaucum) and studying its evolutionary relationship with known XETs from other species (both monocots and dicots)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
