TESTING THE INFLUENCE OF CYP83A1, CYP79F1, AND CYP79F2 IN AUXIN ACCUMULATION AND LATERAL ROOT INITIATION IN ARABIDOPSIS THALIANA

Abstract

The role of CYP83A1, CYP79F1, and CYP79F2 in auxin accumulation and lateral root initiation in Arabidopsis thaliana was explored. These enzymes are at branch points between auxin synthesis and synthesis of plant defense compounds, found in nearly all plants of the order Brassicales, known as glucosinolates: our hypothesis was to test whether these enzymes functioned with XIP1/CEPR1 to control auxin levels or perform some other unknown function. Two lines of knockout or null mutants for each gene were obtained to cross into a line homozygous for a semi-quantitative auxin reporter (R2D2), a null mutation of an auxin biosynthetic enzyme (NIT1), and a receptor that acts in nitrogen foraging and interacts with NIT1 (CEPR1). The genotypes of the CYP83A1 and CYP79F1 knockout lines were confirmed. Both CYP83A1 knockout lines were successfully crossed into the R2D2 line. One of the CYP83A1 lines, ref2-1, was crossed into all the relevant mutants, selfed for three generations and plants homozygous for ref2-1, xip1-1, and R2D2 were isolated; these plants are heterozygous for nit1-1.