Effect of TLD1 on architecture and drought tolerance of rice

Submitted by admin on Mon, 10/05/2009 - 11:40

Zhang et al. (Plant Phys, Sept 23) report the influence of TLD1/GH3.13 (PlantGeneWiki: GR:0020049) gene on plant architecture and drought tolerance through the isolation of a gain of function rice mutant, tld1-D. TLD1 is a IAA-amido synthetase that conjugates free IAA to amino acids, in turn reducing available free IAA in the plant. Its expression is suppressed in above ground regions of the plant but is rapidly induced during drought stress. The activation of TLD1 reduces available IAA in meristematic regions of the shoot thus influencing the growth form such as plant height, leaf angle and number of tillers. The reduction in free IAA also promotes accumulation of drought inducible genes such as late-embryogenesis abundant (LEA) mRNAs and is likely one of the drought adaptation mechanisms in plants.