Location: Molecular Plant Pathology LaboratoryTitle: Characterization of a Beta Vulgaris polygalacturonase-inhibiting protein: a defense response gene Author
Submitted to: American Society of Sugar Beet Technologists
Publication Type: Review Article
Publication Acceptance Date: 4/1/2015
Publication Date: 6/23/2015
Citation: Li, H., Padmanaban, S., Smigocki, A.C. 2015. Characterization of a Beta Vulgaris polygalacturonase-inhibiting protein: A defense response gene . American Society of Sugar Beet Technologists. http://www.bsdf-assbt.org/assbt/Biennial%20Stuff/assbtbienmtg.htm. Interpretive Summary: Diseases and insect pests are responsible for reducing sugar yields from sugar beet, an economically important crop. To better understand how plants protect themselves from insect pests and harmful microbes, we isolated a sugar beet cell wall component (PGIP) that has been shown to inhibit pest and microbe attacks in other plants. The structure of the sugar beet PGIP component responsible for disease response was found to be unique to sugar beet, and it was more abundantly produced in roots as compared to other tissues. Scientists will use this information to develop crops with improved natural pest and disease resistance that will lead to increased yields and reduced usage of chemical pesticide.
Technical Abstract: Polygalacturonase-inhibiting proteins (PGIPs) are plant cell wall proteins that inhibit pathogen and pest polygalacturonases (PGs). PGIPs are members of the leucine-rich repeat (LRR) protein family that play crucial roles in development, pathogen defense and recognition of beneficial microbes in plants. Two sugar beet PGIP genes, Bv(FC607)PGIP1 and Bv(FC607)PGIP2, were cloned from a breeding line FC607. Sequence analysis showed that both genes encoded about 380 amino acids and shared 74.8% sequence similarity. They were most closely matched to PGIPs of a sugar beet line KWS2320 and a subgroup of M. truncatula PGIP (GenBank No: XP_003621816). FCPGIPs exhibited characteristics of other plant PGIPs, including the presence of an N-terminal signal peptide and LRR repeats that were50-60 amino acid longer than has been reported for most other PGIPs. In 2-month old plants, RT-PCR analysis demonstrated that each PGIP gene was expressed constitutively, with maximum expression being observed in roots, followed by leaves then petioles and hypocotyls, suggesting that the gene is developmentally regulated. A study of PGIP inhibitory effect on pathogens and pests is ongoing.