Legumes under Environmental Stress by Parvaiz Ahmad

Author:Parvaiz Ahmad [Ahmad, Parvaiz]
Language: eng
Format: epub
ISBN: 9781118917114
Publisher: Wiley
Published: 2015-01-12T00:00:00+00:00

10.3 Perception of ABA in legumes under abiotic stress

The cell needs to perceive ABA and transduce the signal to cellular components for ABA function. Progress in understanding ABA perception and signal transduction has been achieved recently (Cutler et al., 2010; Raghavendra et al., 2010; Umezawa et al., 2010; Weiner et al., 2010). Most of the studies of ABA receptors have been done in Arabidopsis with a few reports in other plants (Jia et al., 2011; Kim et al., 2012). Recently, ABA receptors and group A 2C-type protein phosphatases were shown to govern the ABA signalling pathway. Moreover, recent studies have suggested that there are interactions between the major ABA signalling pathway and other signalling factors in stress responses and seed and seedling development (Nakashima & Yamaguchi-Shinozaki, 2013). Control of the expression of ABA signalling factors may improve tolerance to environmental stresses.

The PYR/PYL/RCAR family (hereafter referred to as PYLs) is known to include ABA receptors. Ge et al. (2010) reported the characterization of PYL homologues (GmPYLs) in soybean. Twenty-three putative GmPYLs can be found from the soybean genome sequence and categorized into three subgroups. GmPYLs interact with AtABI1 and two GmPP2Cs in diverse ways. Many of the subgroup I GmPYLs interact with PP2Cs in an ABA-dependent manner, whereas most of the subgroup II and III GmPYLs bind to PP2Cs in an ABA-independent manner. The subgroup III GmPYL23, which cannot interact with any of the tested PP2Cs, differs from other GmPYLs. The CL2/gate domain is crucial for GmPYL–PP2C interaction, and a mutation in the conserved proline (P109S) abolishes the interaction between GmPYL1 and AtABI1. Furthermore, GmPYL1 interacts with AtABI1 in an ABA-dependent manner in plant cells. Three GmPYLs differentially inhibit AtABI1 and GmPP2C1 in an ABA-dependent or -enhanced manner in vitro. In addition, ectopically expressed GmPYL1 partially restores ABA sensitivity of the Arabidopsis triple mutant pyr1/pyl1/pyl4. Thus, soybean GmPYLs are ABA receptors that function by interacting and inhibiting PP2Cs.

It has been demonstrated that a protein phosphorylation reaction in ABA signalling involves the participation of several protein kinases (Verslues & Zhu, 2007; Wang et al., 2010). The guard cell-specific protein kinase AAPK from Vicia faba and its orthologue OST1/SnRK2.6 in Arabidopsis are involved in ABA signalling (Yoshida et al., 2002; Rodriguez et al., 2010). Expression of the soybean GmWNK1 is involved in ABA signalling through activation of SPAK and OSR1 triggering a MAPK cascade or different co-transporters regulating ABA-dependent osmotic stresses in legumes (Wang et al., 2010)

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.