bims-plasge 2023-06-25 papers

Issue of 2023–06–25
two papers selected by
Vera S. Bogdanova, ИЦиГ СО РАН

Theor Appl Genet. 2023 Jun 18. 136(7): 156

Molecular genetics of cytoplasmic male sterility and restorer-of-fertility for the fine tuning of pollen production in crops.

Kazuyoshi Kitazaki, Kotoko Oda, Akiho Akazawa, Ryoma Iwahori.

Cytoplasmic male sterility (CMS) is an increasingly important issue within the context of hybrid seed production. Its genetic framework is simple: S-cytoplasm for male sterility induction and dominant allele of the restorer-of-fertility gene (Rf) for suppression of S. However, breeders sometimes encounter a phenotype of CMS plants too complex to be explained via this simple model. The molecular basis of CMS provides clue to the mechanisms that underlie the expression of CMS. Mitochondria have been associated with S, and several unique ORFs to S-mitochondria are thought to be responsible for the induction of male sterility in various crops. Their functions are still the subject of debate, but they have been hypothesized to emit elements that trigger sterility. Rf suppresses the action of S by various mechanisms. Some Rfs, including those that encode the pentatricopeptide repeat (PPR) protein and other proteins, are now considered members of unique gene families that are specific to certain lineages. Additionally, they are thought to be complex loci in which several genes in a haplotype simultaneously counteract an S-cytoplasm and differences in the suite of genes in a haplotype can lead to multiple allelism including strong and weak Rf at phenotypic level. The stability of CMS is influenced by factors such as the environment, cytoplasm, and genetic background; the interaction of these factors is also important. In contrast, unstable CMS becomes inducible CMS if its expression can be controlled. CMS becomes environmentally sensitive in a genotype-dependent manner, suggesting the feasibility of controlling the expression of CMS.

DOI: https://doi.org/10.1007/s00122-023-04398-8

Planta. 2023 Jun 23. 258(2): 25

Domestication has altered the ABA and gibberellin profiles in developing pea seeds.

Jana Balarynová, Barbora Klčová, Danuše Tarkowská, Veronika Turečková, Oldřich Trněný, Martina Špundová, Sergio Ochatt, Petr Smýkal.

MAIN CONCLUSION: We showed that wild pea seeds contained a more diverse combination of bioactive GAs and had higher ABA content than domesticated peas. Although the role of abscisic acid (ABA) and gibberellins (GAs) interplay has been extensively studied in Arabidopsis and cereals models, comparatively little is known about the effect of domestication on the level of phytohormones in legume seeds. In legumes, as in other crops, seed dormancy has been largely or entirely removed during domestication. In this study, we have measured the endogenous levels of ABA and GAs comparatively between wild and domesticated pea seeds during their development. We have shown that wild seeds contained more ABA than domesticated ones, which could be important for preparing the seeds for the period of dormancy. ABA was catabolised particularly by an 8´-hydroxylation pathway, and dihydrophaseic acid was the main catabolite in seed coats as well as embryos. Besides, the seed coats of wild and pigmented cultivated genotypes were characterised by a broader spectrum of bioactive GAs compared to non-pigmented domesticated seeds. GAs in both seed coat and embryo were synthesized mainly by a 13-hydroxylation pathway, with GA29 being the most abundant in the seed coat and GA20 in the embryos. Measuring seed water content and water loss indicated domesticated pea seeds´ desiccation was slower than that of wild pea seeds. Altogether, we showed that pea domestication led to a change in bioactive GA composition and a lower ABA content during seed development.

Keywords: Desiccation; Legume; Maturation; Phytohormones; Pigmentation; Seed-coat

DOI: https://doi.org/10.1007/s00425-023-04184-2