Anatomy and metabolite content of high relative humidity-induced adventitious roots in tomato (Solanum lycopersicum L.)

PAMELA ALELÍ REVOLLAR OCHATOMA; FRANCESCO MIGNOLLI; MARÍA LAURA VIDOZ

Rosario, Santa Fe

Conferencia; Reunión Argentina de Fisiología Vegetal XXXIV; 2023

Sociedad Argentina de Fisiología Vegetal - SAFV

Many environmental and endogenous factors, such as light, temperature and mineralnutrition, affect the development of adventitious roots (ARs). In addition to their economicand ecological importance, developing ARs in response to biotic and abiotic stress iscrucial for plant survival, especially when the primary root system dies. High atmospherichumidity (HH) can trigger AR formation in tomato plants (Solanum lycopersicum L.),involving conspicuous anatomical and metabolic changes. For this reason, we investigatedthe anatomy and the content of sugars and amino acids of ARs that developed in HHcompared with those formed under flooding conditions. Tomato plants of the Ailsa Craigcultivar were grown in 300 cm3 plastic pots in a growth chamber. When plants were fourweeks old, they were placed individually in 1-L plastic containers. The edge of thecontainer was sealed with a gas-permeable plastic film to maintain HH around plant stemswithout limiting gas exchange. Flooding was applied by submerging plant stems with waterup to cotyledons. ARs formed under HH displayed higher soluble sugars (sucrose, glucoseand fructose) and starch content, whereas the concentration of amino acids was similar inboth types of ARs. Anatomically, ARs in HH presented a more compact cortex withexpanded and isodiametric cells, while ARs from flooded plants were characterised by airspaces due to aerenchyma formation. These results indicate that ARs are differentiallyregulated in response to the factor that induces them and that tomato plant stems candistinguish the water potential of the external environment, resulting in the formation ofeither flooding or HH ARs.