PRX2 and PRX25, peroxidases regulated by COG1, are involved in seed longevity in Arabidopsis

Abstract

Permeability is a crucial trait that affects seed longevity and is regulated by different polymers including proanthocyanidins, suberin, cutin and lignin located in the seed coat. By testing mutants in suberin transport and biosynthesis, we demonstrate the importance of this biopolymer to cope with seed deterioration. Transcriptomic analysis of cog1‐2D, a gain‐of‐function mutant with increased seed longevity, revealed the upregulation of several peroxidase genes. Reverse genetics analysing seed longevity uncovered redundancy within the seed coat peroxidase gene family; however, after controlled deterioration treatment, seeds from the prx2 prx25 double and prx2 prx25 prx71 triple mutant plants presented lower germination than wild‐type plants. Transmission electron microscopy analysis of the seed coat of these mutants showed a thinner palisade layer, but no changes were observed in proanthocyanidin accumulation or in the cuticle layer. Spectrophotometric quantification of acetyl bromide‐soluble lignin components indicated changes in the amount of total polyphenolics derived from suberin and/or lignin in the mutant seeds. Finally, the increased seed coat permeability to tetrazolium salts observed in the prx2 prx25 and prx2 prx25 prx71 mutant lines suggested that the lower permeability of the seed coats caused by altered polyphenolics is likely to be the main reason explaining their reduced seed longevity.

The DOF Transcription Factors in Seed and Seedling Development

“…This phenotype is in agreement with the negative role of COG1 in light signalling, since Red and Far Red light have a negative role in seed tolerance to deterioration, as indicated by the increased tolerance of the phyB-9 and phyA-211 mutant seeds [89]. In addition, it has recently been demonstrated that COG1 controls the expression of the peroxidases PRX2 and PRX25, which are involved in the polymerisation of suberin in the seed coat [90]. Also, the Arabidopsis DOF protein, AtDOF4.2 (At4g21030), has been proposed to be involved in seed coat composition and mucilage production [91].…”

Anatomy and Histochemistry of Seed Coat Development of Wild (Pisum sativum subsp. elatius (M. Bieb.) Asch. et Graebn. and Domesticated Pea (Pisum sativum subsp. sativum L.)

“…Cameor, which does not have pigmented or impregnated SC. It has been suggested that soybean SC peroxidase is involved in extensin polymerization, lignification, or suberization [ 59 , 67 ], and recent work on Arabidopsis supports the role of PRX in lignin formation [ 68 , 69 ]. Interestingly, the production of reactive oxygen species (ROS) mediates germination by direct scissoring of cell wall polysaccharides [ 70 ].…”

Identification of novel seed longevity genes related to oxidative stress and seed coat by genome‐wide association studies and reverse genetics

“…enzymes participate in the synthesis of lipid-polyester barriers, such as cutin and suberin (Watson et al, 2001;Compagnon et al, 2009;Kannangara et al, 2007). Recent studies point to an important role of these lipid polyester barriers in seed longevity and tetrazolium impermeability (Beisson et al, 2007;Bueso et al, 2016;Renard et al, 2020;Yadav et al, 2014).…”

“…Moreover, the seed coat has been proposed to be important, especially the endothelium flavonoids (proanthocyanidins; Clerkx, Blankestijn-De Vries, Ruys, Groot, & Koornneef, 2004) and the palisade suberin (Bueso et al, 2014(Bueso et al, , 2016Renard et al, 2020) but the transcription factors and enzymes involved in the development of this structure (Haughn & Chaudhury, 2005) are not completely known.…”