title: Survival strategies of citrus rootstocks subjected to drought.
abstract: Two citrus rootstocks, Rangpur lime (RL) and Sunki Maravilha mandarin (SM), were analyzed either ungrafted or grafted with their reciprocal graft combinations or with shoot scions of two commercial citrus varieties: Valencia orange (VO) and Tahiti acid lime (TAL). All graft combinations were subjected to distinct watering regimes: well-watered, severe drought and rehydration. Growth and water relation parameters, gas exchange as well as sugar and hormone profiles were determined. Data indicated that RL adopted a dehydration avoidance strategy and maintained growth, whereas SM adopted a dehydration tolerance strategy focused on plant survival. Compared with RL, the leaves and roots of SM exhibited higher concentrations of abscisic acid and salicylic acid, which induced drought tolerance, and accumulation of carbohydrates such as trehalose and raffinose, which are important reactive oxygen species scavengers. SM rootstocks were able to transfer their survival strategy to the grafted shoot scions (RL, VO, TAL). Because of their contrasting survival strategies, RL reached the permanent wilting point more quickly than SM whereas SM recovered from prolonged droughts more efficiently than RL. This is one of the most complete studies of drought tolerance mechanisms in citrus crops and is the first to use reciprocal grafting to clarify scion/rootstock interactions.
authors.affiliation: Departamento de Biologia, Centro de Genética and Biologia Molecular, Universidade Estadual de Santa Cruz, Ilhéus, Bahia 45662-900, Brazil.
authors.forename: Dayse Drielly Souza
authors.initials: DD
authors.lastname: Santana-Vieira
authors.affiliation: Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, São Paulo 05508-090, Brazil.
authors.forename: Luciano
authors.initials: L
authors.lastname: Freschi
authors.affiliation: Departamento de Biologia, Centro de Genética and Biologia Molecular, Universidade Estadual de Santa Cruz, Ilhéus, Bahia 45662-900, Brazil.
authors.forename: Lucas Aragão da Hora
authors.initials: LA
authors.lastname: Almeida
authors.affiliation: Departamento de Biologia, Centro de Genética and Biologia Molecular, Universidade Estadual de Santa Cruz, Ilhéus, Bahia 45662-900, Brazil.
authors.forename: Diogo Henrique Santos de
authors.initials: DH
authors.lastname: Moraes
authors.affiliation: Departamento de Biologia, Centro de Genética and Biologia Molecular, Universidade Estadual de Santa Cruz, Ilhéus, Bahia 45662-900, Brazil.
authors.forename: Diana Matos
authors.initials: DM
authors.lastname: Neves
authors.affiliation: Departamento de Ciências Agrárias, Universidade Federal do Recôncavo da Bahia, Cruz das Almas, Bahia 44380-000, Brazil.|Embrapa Mandioca e Fruticultura, Cruz das Almas, Bahia, 44380-000, Brazil.
authors.forename: Liziane Marques Dos
authors.initials: LM
authors.lastname: Santos
authors.affiliation: Departamento de Ensino, Instituto Federal da Bahia, Campus Eunápolis, Eunápolis, Bahia 45823-431, Brazil.
authors.forename: Fabiana Zanelato
authors.initials: FZ
authors.lastname: Bertolde
authors.affiliation: Embrapa Mandioca e Fruticultura, Cruz das Almas, Bahia, 44380-000, Brazil.
authors.forename: Walter Dos Santos
authors.initials: WD
authors.lastname: Soares Filho
authors.affiliation: Embrapa Mandioca e Fruticultura, Cruz das Almas, Bahia, 44380-000, Brazil.
authors.forename: Maurício Antonio
authors.initials: MA
authors.lastname: Coelho Filho
authors.affiliation: Departamento de Biologia, Centro de Genética and Biologia Molecular, Universidade Estadual de Santa Cruz, Ilhéus, Bahia 45662-900, Brazil.|Embrapa Mandioca e Fruticultura, Cruz das Almas, Bahia, 44380-000, Brazil.
authors.forename: Abelmon da Silva
authors.initials: AD
authors.lastname: Gesteira
mesh_terms: D002957:Citrus / Q000378:metabolism*; D003681:Dehydration; D018517:Plant Roots / Q000378:metabolism*; D018520:Plant Shoots / Q000378:metabolism*; D013312:Stress, Physiological