What domestication took away: phytochrome B-mediated responses to environmental change

VUJANIC, T; PINCIAROLI, C; TALARICO, L; FERNANDEZ, PC; MANZUR ME

Rosario, Santa Fé

Congreso; XXXIV Argentinian Meeting of Plant Physiology; 2023

SAFV

Environmental changes impact on plant growth, metabolism and yield. In response, plants can adjust their phenotype and gene expression. However, due to domestication, some responses have been unintentionally modified, such as reduced investment in defences. An example is tomato crop (Solanum lycopersicum L.), which has only 5% of the genetic and chemical diversity of its wild relatives. In this study, the combined effect of high temperature (T) and low Red:Far-Red light ratio (R:FR) on growth and headspace volatiles (VOCs) composition in tomato plants S. lycopersicum and its wild relative S. pimpinellifolium were analyzed. It is hypothesized that S. pimpinellifolium will have a higher growth rate at a low R:FR ratio than its domesticated relative. It is also expected to have a higher VOCs diversity and, thus improved responses against herbivore insects. Seedlings of S. pimpinellifolium (LYC 2875) and the commercial species S. lycopersicum (cv. Moneymaker) were used. The combination of T and light factors resulted in four treatments (White Light and Control Temperature: WL-CT, Far-Red and Control Temperature: FR-CT, White Light and High Temperature: WL-T+, Far-Red and High Temperature: FR-T+), which were applied four weeks after emergence for ten days. Height was periodically recorded, and VOCs were collected at the end. Preliminary results show that growth rate was similar among genotypes, although there was an effect of the combined treatments (FR-T+ vs. WL-CT: P=0.045). The effects on final height in S. pimpinellifolium would be explained mainly by the effect of Far-Red and not by temperature since growth was inhibited at 30 °C (WL-T+ vs. WL-CT: P=0.618). It is concluded that the phenotypic plasticity of wild species should be considered to improve the response of domesticated species to deal with environmental changes.