It is well known that the phytohormones abscisic acid (ABA) and indole-3-acetic acid (IAA) response pathways interact synergistically or antagonistically to regulate plant development and environmental adaptation, and many players in both phytohormones have been uncovered, but the
fundamental mechanisms underlying their interconnection remain rudimentary.
Recently, a research team led by Prof. XIE Qi in the Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, found that Endoplasmic reticulum-localized small heat shock protein 22 (sHSP22) regulates auxin response through modulating auxin polar transport, and ABI1-sHSP22 provides a novel module orchestrating ABA and auxin signaling crosstalk in Arabidopsis.
They found the mutation in ABI1 resulted in decreased sensitivity to auxin in lateral root formation. Further analysis showed that sHSP22 expression is ABI1-dependent. They then found that sHSP22 negatively regulates ABA responses and promotes the auxin-induced lateral root formation by affecting intracellular vesicle trafficking of PIN proteins.
This work provides knowledge to understand the novel mechanism between ABA and auxin signaling crosstalk.
This relevant work entitled “
The sHSP22 heat-shock protein requires the ABI1 protein phosphatase to modulate polar auxin transport and downstream responses” has been published in
Plant Physiology on 29 Dec. 2017 (
https://doi.org/10.1104/pp.17.01206).
This research is supported by grants from the National Key R&D Program of China grants and the National Science Foundation of China.
Figure1. Hypothesized model of sHSP22 action in auxin and ABA crosstalk (Image by IGDB)
