Response mechanisms of secondary meristem to abiotic stresses: drought effect on water and carbon relations in poplar

This PhD project is focused on the carbon and water relations during drought and the aim is to advance the current understanding on the mechanisms underlying the water deficit response. The goal is to comprehend: i) the genotype-dependent features involved in the different response to drought of poplar species in the stem, particularly in cambial region; ii) the sink-source variations in the carbon and water balances in the different plant compartments under water deficit; iii) the role of carbohydrates in the osmotic processes and their preferential use under stress conditions. According with these aims, three experiments have been carried out: a) Study of the genotype-dependent features involved in the different response to drought of poplar species. In this work two different poplar species were used, Populus alba (L.) and Populus deltoides (Marsh.), to evaluate the response to water deficit and rehydration in water and carbohydrate relationships in cambial region. b) Study of the role of carbohydrates, as osmotically active molecules, in water deficit response in P. alba, focusing on the daily carbon and water balances within different tissues. c) Study of the carbohydrate and water balances in poplar callus-medium system under osmotic stress and how these relationships can influence the osmoregulation and the growth.