Drought‐induced protein (Di19‐3) plays a role in auxin signaling by interacting with IAA14 in Arabidopsis

Abstract

The members of early auxin response gene family, Aux/IAA, encode negative regulators of auxin signaling but play a central role in auxin‐mediated plant development. Here we report the interaction of an Aux/IAA protein, AtIAA14, with Drought‐induced‐19 (Di19‐3) protein and its possible role in auxin signaling. The Atdi19‐3 mutant seedlings develop short hypocotyl, both in light and dark, and are compromised in temperature‐induced hypocotyl elongation. The mutant plants accumulate more IAA and also show altered expression of NIT2, ILL5, and YUCCA genes involved in auxin biosynthesis and homeostasis, along with many auxin responsive genes like AUX1 and MYB77. Atdi19‐3 seedlings show enhanced root growth inhibition when grown in the medium supplemented with auxin. Nevertheless, number of lateral roots is low in Atdi19‐3 seedlings grown on the basal medium. We have shown that AtIAA14 physically interacts with AtDi19‐3 in yeast two‐hybrid (Y2H), bimolecular fluorescence complementation, and in vitro pull‐down assays. However, the auxin‐induced degradation of AtIAA14 in the Atdi19‐3 seedlings was delayed. By expressing pIAA14::mIAA14‐GFP in Atdi19‐3 mutant background, it became apparent that both Di19‐3 and AtIAA14 work in the same pathway and influence lateral root development in Arabidopsis. Gain‐of‐function slr‐1/iaa14 (slr) mutant, like Atdi19‐3, showed tolerance to abiotic stress in seed germination and cotyledon greening assays. The Atdi19‐3 seedlings showed enhanced sensitivity to ethylene in triple response assay and AgNO3, an ethylene inhibitor, caused profuse lateral root formation in the mutant seedlings. These observations suggest that AtDi19‐3 interacting with AtIAA14, in all probability, serves as a positive regulator of auxin signaling and also plays a role in some ethylene‐mediated responses in Arabidopsis.Significance StatementThis study has demonstrated interaction of auxin responsive Aux/IAA with Drought‐induced 19 (Di19) protein and its possible implication in abiotic stress response.

Homologous Drought-Induced 19 Proteins, PtDi19-2 and PtDi19-7, Enhance Drought Tolerance in Transgenic Plants

“…Recently, Di19 protein has been assigned to be involved in hormonal interactions in plant development. AtDi19-3 interacted with AtIAA14 as a positive regulator of auxin signaling and plays a role in some ethylene-mediated responses in Arabidopsis [ 26 ]. These studies suggested that Di19 family genes play crucial role in growth and development and abiotic stress response.…”

Genome-Wide Association Study Reveals Genetic Architecture and Candidate Genes for Yield and Related Traits under Terminal Drought, Combined Heat and Drought in Tropical Maize Germplasm

“…In an effort to select potential candidate genes for cloning and functional verification using gene overexpression and CRISPR/Cas technology, a number of candidate genes were predicted based on propelling evidence from in silico and could be validated to unravel their actual regulatory role in the studied traits. For instance, recent evidence suggest that Auxin induced-like protein ( Zm00001d002374 ) predicted in the present study is reported to play a significant role under drought or heat and combined heat and drought stress in Arabidopsis [ 79 , 80 ]. Circadian clock and CARES are known to regulate gene expression under different conditions [ 81 ].…”

R2R3-MYB Transcription Factor Family in Boehmeria nivea (L.) Gaudich: Potential Associations between Cd2+ Stress and Flavonoid Metabolism

“…In ramie, we found their respective homologous genes, BnGMYB9 and BnGMYB 104 and their expression patterns were similar to those of AtMYB49/59 under cadmium treatment [69,70], so we deduced that they also had similar functions. BnGMYB45/89/90 which fall to the C33 group were according to phylogenetic analysis valuable candidate for abiotic stress [71][72][73]. Taken together, these above ndings might be valuable for improving the cadmium resistance of ramie via the manipulation of the BnGMYBs.…”