Genetic Interactions during Root Hair Morphogenesis in Arabidopsis

Abstract

Root hairs are a major site for the uptake of water and nutrients into plants and form an increasingly important model system for studies of development of higher plants and cell biology. We have identified loss-of-function mutations in eight new genes required for hair growth in Arabidopsis: SHAVEN1 ( SHV1 ), SHV2 , and SHV3 ; CENTIPEDE1 ( CEN1 ), CEN2 , and CEN3 ; BRISTLED1 ( BST1 ); and SUPERCENTIPEDE1 ( SCN1 ). We combined mutations in 79 pairs of genes to determine the stages at which these and six previously known genes contribute to root hair formation. Double mutant phenotypes revealed roles for several genes that could not have been predicted from the single mutant phenotypes . For example, we show that TIP1 and RHD3 are required much earlier in hair formation than previous studies have suggested. We present a genetic model for root hair morphogenesis that defines the roles of each gene, and we suggest hypotheses about functional relationships between genes.

Wax constituents on the inflorescence stems of double eceriferum mutants in Arabidopsis reveal complex gene interactions

“…The following discussion will focus on the most dramatic and sometimes unexpected effects of CER (Bowman et al, 1993(Bowman et al, , 2002Scortecci et al, 2003), leaf (Serrano-Cartagena et al, 2002), and root development (Parker et al, 2000), stress signaling (Nibbe et al, 2002), and various carbohydrate and lipid metabolic pathways (Cano-Delgado et al, 2000;Niyogi et al, 2001;Thummel and Chory, 2002;Rylott et al, 2003), the double mutant analysis of cer gene interactions presented here is the first of its kind for plant wax synthesis, and among the most extensive for any plant metabolic network. Five of the 14 double cer mutants, cer1 cer3, cer2 cer3, cer6 cer9, cer8 cer9, and cer8 cer19, produced significantly more total wax than at least one of their respective cer parents, indicating genetically a partial bypassing (or partial complementation) of one cer mutation by the other.…”

Regulation of Cell Division and Growth in Roots of Lactuca sativa L. Seedlings by the Ent-Kaurene Diterpenoid Rabdosin B

“…Research will be needed in order to understand the ecological conditions necessary for hormesis and the potential impacts of low dose stimulation by the diterpenoid. Parker et al (2000) reported that root hairs contribute as much as 77% to the total root surface area in cultivated crops, being the major point of contact between plants and the rhizosphere. Our results indicate that rabdosin B strongly inhibits root hair development in a dose-dependent manner.…”

QTL mapping of root hair and acid exudation traits and their relationship to phosphorus uptake in common bean

“…Genetic analysis of Arabidopsis has suggested that there is a complicated network controlling roothair initiation and growth, involving many genes of various functions (Parker et al, 2000). Different genes might be involved for root-hair initiation (which determines the density of root hairs) and root-hair elongation (which determines the total length of root hairs) (Schiefelbein and Somerville, 1990).…”