Evidence for participation of the methionine sulfoxide reductase repair system in plant seed longevity

Abstract

Seeds are in a natural oxidative context leading to protein oxidation. Although inevitable for proper progression from maturation to germination, protein oxidation at high levels is detrimental and associated with seed aging. Oxidation of methionine to methionine sulfoxide is a common form of damage observed during aging in all organisms. This damage is reversible through the action of methionine sulfoxide reductases (MSRs), which play key roles in lifespan control in yeast and animal cells. To investigate the relationship between MSR capacity and longevity in plant seeds, we first used two Medicago truncatula genotypes with contrasting seed quality. After characterizing the MSR family in this species, we analyzed gene expression and enzymatic activity in immature and mature seeds exhibiting distinct quality levels. We found a very strong correlation between the initial MSR capacities in different lots of mature seeds of the two genotypes and the time to a drop in viability to 50% after controlled deterioration. We then analyzed seed longevity in Arabidopsis thaliana lines, in which MSR gene expression has been genetically altered, and observed a positive correlation between MSR capacity and longevity in these seeds as well. Based on our data, we propose that the MSR repair system plays a decisive role in the establishment and preservation of longevity in plant seeds.seed deterioration | seed viability | redox systems | antioxidant enzymes S uccessful crop implantation is crucial for maximal plant yield and relies on seed physiological quality, which is acquired at the end of development, during maturation. Quality is expressed by the capacity of seeds to germinate in a fast and homogenous manner before and after storage (seed longevity) and to provide proper seedling establishment in various environments (seed vigor). Quality is controlled by genetic traits and varies greatly among species and cultivars. The establishment of quality also depends on the prevailing environmental conditions during seed development and storage (1, 2).During the maturation phase, mechanisms are put in place to prevent and repair desiccation damage, as well as to allow survival of seeds in the dry state (3-5). Nonetheless, drying of seeds on mother plants can occur prematurely in drought conditions, leading to low-quality seeds (6-8). Thus, in the context of a warming climate, producing good-quality seeds represents a global challenge to sustain current yield levels (9, 10).The mechanisms underlying seed quality are controlled in part by abscisic acid (ABA), the phytohormone involved in plant responses to dehydration that is produced during seed maturation. Of note, ABA triggers the accumulation of late-embryogenesis abundant proteins, heat-shock proteins (HSPs), and storage proteins (11). Late-embryogenesis abundant proteins and HSPs are thought to primarily protect cell structures when water is removed. Reserve proteins, through their sensitivity to reactive oxygen species (ROS), play a determinant role in limiting oxidative damage...

ARABIDOPSIS THALIANA HOMEOBOX25 Uncovers a Role for Gibberellins in Seed Longevity

“…Most mutants in seed longevity are of two types: recessive mutants, with poor longevity affected in genes required for seed development (such as lec1, lec2, fus3, and abi3; Holdsworth et al, 1999;Clerkx et al, 2003Clerkx et al, , 2004, and dominant mutants, with improved longevity obtained by reverse genetics overexpressing stress defenses and repair systems such as small heat shock proteins (Prieto-Dapena et al, 2006), Met sulfoxide reductase (Châtelain et al, 2013), DNA glycosylase/AP lyase (Chen et al, 2012), and L-isoaspartyl methyltransferase (Ogé et al, 2008). To our knowledge, our athb25-1D mutant is the first mutant obtained by forward genetics and the first dominant mutant not related Figure 7.…”

“…Reactive oxygen species induce lipid oxidation, and Arabidopsis (Arabidopsis thaliana) mutants (vitamin E deficient1 and vitamin E deficient2) affected in the biosynthesis of vitamin E (tocopherol, a lipophilic antioxidant) produce seeds with reduced longevity (Sattler et al, 2004). Repair of oxidized proteins by Met sulfoxide reductase (Châtelain et al, 2013), of oxidized DNA by DNA glycosylase/ Apurinic/Apyrimidinic lyase (Chen et al, 2012), and of chemically degraded proteins by L-isoaspartyl methyltransferase (Ogé et al, 2008) enhances seed longevity. Other important factors are chaperones or heat shock proteins.…”

Protein repair l -isoaspartyl methyltransferase 1 (PIMT1) in rice improves seed longevity by preserving embryo vigor and viability

“…Two DNA repair enzymes, AtLIG6 and AtOGG1, repair DNA damage in seeds under stress, thus extending seed longevity (Chen et al 2012;Waterworth et al 2010). Another important protein repair system, the methionine sulfoxide reductase repair system, has recently been shown to play a key role in the establishment and preservation of seed longevity (Chatelain et al 2013). These findings draw attention to the role of the plant's own repair systems and their effects on seed longevity and germination vigor.…”

“…Plant seeds have a very low metabolic activity and resource use capability, which means that protein de-novo synthesis almost ceases (Rajjou et al 2012). To achieve homeostasis when exposed to aging, seeds use repair systems that have a low resource and energy cost to alleviate and repair damage without de-novo synthesis (Chatelain et al 2013;Oge et al 2008;Verma et al 2013). Spontaneous formation of abnormal isoaspartyl (isoAsp) residues from Laspartyl or L-asparaginyl residues in proteins is a common form of protein covalent damage in cells and tissues.…”

Identification of Biomarkers for Resistance to Fusarium oxysporum f. sp. cubense Infection and in Silico Studies in Musa paradisiaca Cultivar Puttabale through Proteomic Approach

“…ROS readily oxidizes Met residues in proteins/peptides to form Met-Rsulfoxide or Met-S-sulfoxide, resulting in the inactivation or malfunction of the proteins. Methionine sulfoxide reductases catalyzes the reduction of methionine sulfoxide (MetSO) to methionine in proteins and plays a protective role against oxidative stress by restoring activity to proteins that have been inactivated by methionine oxidation [27,28,29,30]. Swarupa et al [31] reported current research on oxidative burst and antioxidant enzymes, i.e.…”