TY - JOUR

T1 - Rootstock-mediated changes in xylem ionic and hormonal status are correlated with delayed leaf senescence and increased leaf area and crop productivity in salinised tomato.

AU - Albacete, Alfonso

AU - Martínez-Andújar, Cristina

AU - Ghanem, Michel Edmond

AU - Acosta, Manuel

AU - Sanchez-Bravo, Jose

AU - Asins, Maria J.

AU - Cuartero, Jesus

AU - Lutts, Stanley

AU - Dodd, Ian C.

AU - Pérez-Alfocea, Francisco

PY - 2009/7

Y1 - 2009/7

N2 - Tomato crop productivity under salinity can be improved by grafting cultivars onto salt-tolerant wild relatives, thus mediating the supply of root-derived ionic and hormonal factors that regulate leaf area and senescence. A tomato cultivar was grafted onto rootstocks from a population of recombinant inbred lines (RILs) derived from a Solanum lycopersicum × Solanum cheesmaniae cross and cultivated under moderate salinity (75 mm NaCl). Concentrations of Na+, K+ and several phytohormones [abscisic acid (ABA); the cytokinins (CKs) zeatin, Z; zeatin riboside, ZR; and the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC)] were analysed in leaf xylem sap in graft combinations of contrasting vigour. Scion leaf area correlated with photosystem II (PSII) efficiency (Fv/Fm) and determined fruit productivity. Xylem K+ (but not Na+), K+/Na+, the active CK Z, the ratio with its storage form Z/ZR and especially the ratio between CKs and ACC (Z/ACC and Z + ZR/ACC) were positively loaded into the first principal component (PC) determining both leaf growth and PSII efficiency. In contrast, the ratio ACC/ABA was negatively correlated with leaf biomass. Although the underlying physiological mechanisms by which rootstocks mediate leaf area or chlorophyll fluorescence (and thus influence tomato salt tolerance) seem complex, a putative potassium–CK interaction involved in regulating both processes merits further attention.

AB - Tomato crop productivity under salinity can be improved by grafting cultivars onto salt-tolerant wild relatives, thus mediating the supply of root-derived ionic and hormonal factors that regulate leaf area and senescence. A tomato cultivar was grafted onto rootstocks from a population of recombinant inbred lines (RILs) derived from a Solanum lycopersicum × Solanum cheesmaniae cross and cultivated under moderate salinity (75 mm NaCl). Concentrations of Na+, K+ and several phytohormones [abscisic acid (ABA); the cytokinins (CKs) zeatin, Z; zeatin riboside, ZR; and the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC)] were analysed in leaf xylem sap in graft combinations of contrasting vigour. Scion leaf area correlated with photosystem II (PSII) efficiency (Fv/Fm) and determined fruit productivity. Xylem K+ (but not Na+), K+/Na+, the active CK Z, the ratio with its storage form Z/ZR and especially the ratio between CKs and ACC (Z/ACC and Z + ZR/ACC) were positively loaded into the first principal component (PC) determining both leaf growth and PSII efficiency. In contrast, the ratio ACC/ABA was negatively correlated with leaf biomass. Although the underlying physiological mechanisms by which rootstocks mediate leaf area or chlorophyll fluorescence (and thus influence tomato salt tolerance) seem complex, a putative potassium–CK interaction involved in regulating both processes merits further attention.

KW - tomato (Solanum lycopersicum L.) • abscisic acid • 1-aminocyclopropane-1-carboxylic acid • grafting • hormones • potassium • principal component analysis • salt stress • zeatin • zeatin riboside

UR - http://www.scopus.com/inward/record.url?scp=66249130984&partnerID=8YFLogxK

U2 - 10.1111/j.1365-3040.2009.01973.x

DO - 10.1111/j.1365-3040.2009.01973.x

M3 - Journal article

VL - 32

SP - 928

EP - 938

JO - Plant, Cell and Environment

JF - Plant, Cell and Environment

SN - 0140-7791

IS - 7

ER -