Non‐redundant functions of the dimeric ABA receptor Bd PYL 1 in the grass Brachypodium
Summary Abiotic stresses have severe detrimental effects on agricultural productivity worldwide. Abscisic acid ( ABA ) levels rise in response to abiotic stresses, and play a role in coordinating physiological responses. ABA elicits its effects by binding a family of soluble receptors, increasing af...
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Published in | The Plant journal : for cell and molecular biology Vol. 92; no. 5; pp. 774 - 786 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
01.12.2017
|
Online Access | Get full text |
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Summary: | Summary
Abiotic stresses have severe detrimental effects on agricultural productivity worldwide. Abscisic acid (
ABA
) levels rise in response to abiotic stresses, and play a role in coordinating physiological responses.
ABA
elicits its effects by binding a family of soluble receptors, increasing affinity of the receptors to type 2C phosphatases (
PP
2Cs) leading to phosphatase inhibition. In the current study, we conducted a comprehensive analysis of the
ABA
signaling pathway in the cereal model grass
Brachypodium distachyon
. The
Brachypodium
genome encodes a family of 10 functionally conserved
ABA
receptors. The 10th in the series,
Bd
PYL
10
, encodes a defective receptor and is likely a pseudogene. Combinatorial protein interaction assay further validated computational analysis, which grouped
Brachypodium
ABA
receptors into three subfamilies, similarly to
Arabidopsis
classification.
Brachypodium
subfamily
III
receptors inhibited
PP
2C activity
in vitro
and complemented
Arabidopsis
quadruple (
pyr1/pyl1/pyl2/pyl4
) mutant.
Bd
PYL
1
T‐
DNA
mutant exhibited clear
ABA
hyposensitivity phenotypes during seedling establishment and in mature plants. Single receptor predominance is in agreement with high transcriptional abundance of only a small
Brachypodium
ABA
receptors subset, harboring the higher marginal significance of
Bd
PYL
1
. Our findings suggest that unlike the highly redundant
ABA
core signaling components of
Arabidopsis
,
Brachypodium
encompasses a more compact and specialized
ABA
receptor apparatus. This organization may contribute to plant adaptations to ecological niches. These results lay the groundwork for targeting the prominent
ABA
receptors for stress perception in grasses, and reveal functional differences and commonalities between monocots and eudicots.
Significance Statement
Genetic evidence indicates that
Arabidopsis
perceive the stress hormone ABA via a large redundant family of receptors. Although the genome of grass model plant
Brachypodium
encodes similar number of receptors, the expression of
BdPYL1
is predominant and its function during plant development is non‐redundant, from seed to maturation. Suggesting a different strategy to stress perception. |
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ISSN: | 0960-7412 1365-313X |
DOI: | 10.1111/tpj.13714 |