Prediction of Germination in Aged Seeds and Identification of New Seed Viability Biomarkers Using NMR Metabolomics.

The fast evaluation of seed performance is crucial for the agricultural industry. In this work, we apply NMR to identify specific metabolites that are related to the germination capacity of seeds. As our results show, NMR is a fast method with great potential to discover new accumulated metabolites during seed ageing and to predict the germination of a seed batch.

Endosperm Persistence in Results in Seed Coat Fractures and Loss of Seed Longevity.

Seeds are specialized plant organs that carry, nurture, and protect plant offspring. Developmental coordination between the three genetically distinct seed tissues (the embryo, endosperm, and seed coat) is crucial for seed viability. In this study, we explore the relationship between the TFs AtHB25 and ICE1.

Seed coat lignification level is crucial in Capsicum spp seed longevity.

Capsicum (pepper) is known for its poor seed germination, particularly seed longevity is usually much shorter than other Solanaceae. However, the molecular mechanisms involved are mostly unknown in these species. The present study examines the differences in seed longevity among Capsicum species and varietal types.

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

Seed longevity is a polygenic trait of relevance for agriculture and for understanding the effect of environment on the ageing of biological systems. In order to identify novel longevity genes, we have phenotyped the natural variation of 270 ecotypes of the model plant, Arabidopsis thaliana, for natural ageing and for three accelerated ageing methods. Genome-wide analysis, using publicly available single-nucleotide polymorphisms (SNPs) data sets, identified multiple genomic regions associated with variation in seed longevity.

An Mutant Over-Expressing Subtilase SBT4.13 Uncovers the Role of Oxidative Stress in the Inhibition of Growth by Intracellular Acidification.

Intracellular acid stress inhibits plant growth by unknown mechanisms and it occurs in acidic soils and as consequence of other stresses. In order to identify mechanisms of acid toxicity, we screened activation-tagging lines of for tolerance to intracellular acidification induced by organic acids. A dominant mutant, , was isolated twice and shown to over-express subtilase SBT4.

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

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.

A mechanism of growth inhibition by abscisic acid in germinating seeds of Arabidopsis thaliana based on inhibition of plasma membrane H+-ATPase and decreased cytosolic pH, K+, and anions.

The stress hormone abscisic acid (ABA) induces expression of defence genes in many organs, modulates ion homeostasis and metabolism in guard cells, and inhibits germination and seedling growth. Concerning the latter effect, several mutants of Arabidopsis thaliana with improved capability for H(+) efflux (wat1-1D, overexpression of AKT1 and ost2-1D) are less sensitive to inhibition by ABA than the wild type. This suggested that ABA could inhibit H(+) efflux (H(+)-ATPase) and induce cytosolic acidification as a mechanism of growth inhibition.

Peptidyl-prolyl cis-trans isomerase ROF2 modulates intracellular pH homeostasis in Arabidopsis.

Intracellular pH must be kept close to neutrality to be compatible with cellular functions, but the mechanisms of pH homeostasis and the responses to intracellular acidification are mostly unknown. In the plant Arabidopsis thaliana, we found that intracellular acid stress generated by weak organic acids at normal external pH induces expression of several chaperone genes, including ROF2, which encodes a peptidyl-prolyl cis-trans isomerase of the FK506-binding protein class. Loss of function of ROF2, and especially double mutation of ROF2 and the closely related gene ROF1, results in acid sensitivity.

Anti-tumour potential of a gallic acid-containing phenolic fraction from Oenothera biennis.

A phenolic fraction purified form defatted seeds of Oenothera biennis promoted selective apoptosis of human and mouse bone marrow-derived cell lines following first-order kinetics through a caspase-dependent pathway. In non-leukemia tumour cell lines, such as human colon carcinoma CaCo(2) cells and mouse fibrosarcoma WEHI164 cells, this fraction inhibited (3)H-thymidine incorporation but not cell death or cell cycle arrest. Human peripheral blood mononuclear cells showed low sensitivity to treatment.