Natural variation for flower and seed abortion in fluctuating environments

PETRELLI, MARÍA VICTORIA; HERRERA, CAMILA; SEGATTO, LAUTARO; BLANCO, NICOLÁS E.; FUSARI, CORINA M.

Rosario

Congreso; SAIB 2023; 2023

Biotechnology and agriculture have the challenge to secure food for the continuous growing populationin a context jeopardized by the current climate-change scenario. Thus, crop improvement is necessaryto identify varieties with improved yield performance, even under stress conditions. Yield is severelyimpacted by flower and seed abortion due to carbon shortfall early in the reproductive phase(Lauxmann et al., 2016). Identifying genes controlling such process would enable to develop newvarieties with enhance adaptation in fluctuating environments. The era of Next Generation Sequencingand the advantages of using a diverse population in the process of mapping complex traits, haveenabled Genome Wide Association Studies to be a routine toolkit for discovering new genes and alleles.In our laboratory we aim to identify genes regulating the process fruit and seed abortion, and theresuming of reproduction in Arabidopsis thaliana, through Genome Wide Association Studies.To explore the natural variation in the process of abortion and resuming of reproduction, a set of 21ecotypes was subjected to 4 days of extended darkness after the appearing of 2 to 3 siliques. In parallel,the same ecotypes were grown in normal conditions. We characterize: number of total aborted siliques,cm of the stem with aborted flowers, ratio of aborted/non-aborted siliques, number of days until normalreproduction is restored, seed yield (g of total seeds harvested), seed viability (germination power) andcarbon status before and after the treatment. In addition, we explored the pollen physiology of stressedand control plants and evaluate photosynthetic parameters in both panels.Overall, we found that there is a differential response among ecotypes in yield and photosynthetic traitsin the two environmental setups. The increase in seed abortion seen for plants subjected to extendeddarkness is accompanied by a response in the photosynthetic process, i.e., a decrease in Phi2 and anincrease in the NPQT. These results imply a response towards adaptation to stress. In summary,individual or a combination of several traits could be used to perform GWAS and identify candidategenes involved in the regulation of flower and seed abortion. In the long term, we expect to deliver newtools for marker-assisted breeding and crop improvement.