Yeast complementation reveals a role for an Arabidopsis thaliana late embryogenesis abundant (LEA)‐like protein in oxidative stress tolerance

Abstract

SummaryA functional cloning approach using the oxidant-sensitive yeast mutant, Dyap1, was employed to identify plant genes involved in tolerance of oxidative stress. In this screen, we identified an Arabidopsis late embryogenesisabundant (LEA)-like protein, AtLEA5, which increased the tolerance of Dyap1 cells to the oxidants H 2 O 2 , diamide, menadione and tert-butyl hydroperoxide. Unlike canonical LEAs, AtLEA5 is constitutively expressed in roots and reproductive organs but not in seeds. In leaves of short-day grown plants, AtLEA5 transcripts exhibited a diurnal pattern of regulation, where transcripts were repressed in the light and abundant in the dark. Expression of AtLEA5 in leaves was induced by oxidants, ABA and dehydration. Use of abi1-1 (ABAinsensitive) and aba1-1 (ABA-deficient) Arabidopsis mutants indicated that drought induction of AtLEA5 required ABA synthesis but was independent of the ABI1 gene product. Abscisic acid and H 2 O 2 induction of AtLEA5 was also independent of the OXI1 protein kinase. Constitutive overexpression of AtLEA5 resulted in increased root growth and shoot biomass, both in optimal conditions and under H 2 O 2 stress. However, in comparison with wild type, photosynthesis in overexpressing plants was more susceptible to drought. These features suggest that AtLEA5 has a unique function among LEA proteins in that it plays a specific role in protection against oxidative stress involving decreased photosynthesis. This protein functions as part of a complex network of defences that contribute to robustness of plants under stress by minimizing the negative effects of oxidation.

The Ubiquitous Distribution of Late Embryogenesis Abundant Proteins across Cell Compartments in Arabidopsis Offers Tailored Protection against Abiotic Stress

“…LEA38 was recently identified in mitochondria, which is consistent with our observations, and proposed to play major roles in plant development as well as abiotic and biotic stress responses (Salleh et al, 2012). Since the protein was previously shown to improve oxidative stress tolerance when expressed in yeast (Mowla et al, 2006), an interaction of LEA38 with enzymes involved in mitochondrial reactive oxygen species metabolism and signaling was suggested to mediate the pleiotropic effects observed in overexpressor or antisense Arabidopsis lines (Salleh et al, 2012). The two other mitochondrial proteins (LEA37 and 41), as well as the cytosolic LEA2, share similar sequence properties, which would suggest analogous molecular functions (albeit in a different compartment for LEA2).…”

An Unusual Intrinsically Disordered Protein from the Model Legume Lotus japonicus Stabilizes Proteins in Vitro

“…Furthermore, 28IDP1 is depleted in proline residues compared with Disprot 3.4. It is worth noting that the only three proline residues found in LjIDP1 are located in a short conserved proline-rich domain 64 …”

The TvPirin Gene Is Necessary for Haustorium Development in the Parasitic Plant Triphysaria versicolor

“…TvLEA is homologous to genes encoding Late Embryogenesis Abundant (LEA) proteins in Arabidopsis. Both glutathione S-transferase (GST) and LEA transcripts are differentially regulated in nonparasitic plants by various biotic and abiotic stresses (Mowla et al, 2006;Sappl et al, 2009). TvECP has weak homology to several putative plant cytochrome P450 monooxygenases.…”