Sharma, Mandeep , Chopra, Surinder .
Red Aleurone1 of Zea mays is required and independently regulated in phlobaphene and anthocyanin biosynthesis.
Anthocyanins, flavonones, flavones and phlobaphenes are produced through the flavonoid biosynthesis pathway. Flavonoid 3’ hydroxylase (F3’H) is a cytochrome P450 dependent enzyme that plays an important role in generating metabolite diversity by adding a hydroxyl group at 3’ position of the B-ring. It was demonstrated earlier that functional red aleurone1 (pr1) locus may encode for F3’H enzyme in maize. Here, we show that f3’h is regulated by transcription factors of anthocyanin as well as phlobaphene biosynthetic pathways in maize. To study the role of f3’h in different branches of flavonoid biosynthesis, a putative f3’h sequence was isolated from maize. Genetic complementation of pr1 using BMS cell line, germinating maize kernels and Arabidopsis thaliana tt7 mutant confirmed that the isolated sequence encodes for a functional F3’H protein. We provide molecular and biochemical evidences that mutation in functional pr1 locus leads to accumulation of the red colored pelargonidin pigment instead of the purple colored cyanidin in aleurone tissue. Additionally, we show that in a segreagating population, light red colored apiferol as compared to dark red luteoforol accumulates in the cob tissue of mutant pr1 maize ears. Expression of c1, r1 and f3’h along with other genes in the anthocyanin biosynthetic pathway was observed in silk, husk and aleurone tissues in plants carrying functional pr1. f3’h transcript was not detected in mutant pr1 plants. Similarly, lines carrying functional p1 gene shows the expression of f3’h while lines carrying recessive p1 alleles did not show f3’h expression. Additional molecular data showing the possible lesion in the pr1 mutant allele under study will be presented.
Log in to add this item to your schedule
1 - Pennsylvania State Univeristy, Crop and Soil Sciences, 213, ASI Bldg, University Park, Pennsylvania, 16802, USA
2 - Pennsylvania State Univeristy, Crop and Soil Sciences
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM