Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Root-synthesized cytokinins improve shoot growth and fruit yield in salinized tomato (Solanum lycopersicum L.) plants
AU - Ghanem, Michel Edmond
AU - Albacete, Alfonso
AU - Smigocki, Ann C.
AU - Frebort, Ivo
AU - Pospisilova, Hana
AU - Martinez-Andujar, Cristina
AU - Acosta, Manuel
AU - Sanchez-Bravo, Jose
AU - Lutts, Stanley
AU - Dodd, Ian C.
AU - Perez-Alfocea, Francisco
PY - 2011/1
Y1 - 2011/1
N2 - Salinity limits crop productivity, in part by decreasing shoot concentrations of the growth-promoting and senescence-delaying hormones cytokinins. Since constitutive cytokinin overproduction may have pleiotropic effects on plant development, two approaches assessed whether specific root-localized transgenic IPT (a key enzyme for cytokinin biosynthesis) gene expression could substantially improve tomato plant growth and yield under salinity: transient root IPT induction (HSP70::IPT) and grafting wild-type (WT) shoots onto a constitutive IPT-expressing rootstock (WT/35S::IPT). Transient root IPT induction increased root, xylem sap, and leaf bioactive cytokinin concentrations 2- to 3-fold without shoot IPT gene expression. Although IPT induction reduced root biomass (by 15%) in control (non-salinized) plants, in salinized plants (100 mM NaCl for 22 d), increased cytokinin concentrations delayed stomatal closure and leaf senescence and almost doubled shoot growth (compared with WT plants), with concomitant increases in the essential nutrient K+ (20%) and decreases in the toxic ion Na+ (by 30%) and abscisic acid (by 20-40%) concentrations in transpiring mature leaves. Similarly, WT/35S::IPT plants (scion/rootstock) grown with 75 mM NaCl for 90 d had higher fruit trans-zeatin concentrations (1.5- to 2-fold) and yielded 30% more than WT/non-transformed plants. Enhancing root cytokinin synthesis modified both shoot hormonal and ionic status, thus ameliorating salinity-induced decreases in growth and yield.
AB - Salinity limits crop productivity, in part by decreasing shoot concentrations of the growth-promoting and senescence-delaying hormones cytokinins. Since constitutive cytokinin overproduction may have pleiotropic effects on plant development, two approaches assessed whether specific root-localized transgenic IPT (a key enzyme for cytokinin biosynthesis) gene expression could substantially improve tomato plant growth and yield under salinity: transient root IPT induction (HSP70::IPT) and grafting wild-type (WT) shoots onto a constitutive IPT-expressing rootstock (WT/35S::IPT). Transient root IPT induction increased root, xylem sap, and leaf bioactive cytokinin concentrations 2- to 3-fold without shoot IPT gene expression. Although IPT induction reduced root biomass (by 15%) in control (non-salinized) plants, in salinized plants (100 mM NaCl for 22 d), increased cytokinin concentrations delayed stomatal closure and leaf senescence and almost doubled shoot growth (compared with WT plants), with concomitant increases in the essential nutrient K+ (20%) and decreases in the toxic ion Na+ (by 30%) and abscisic acid (by 20-40%) concentrations in transpiring mature leaves. Similarly, WT/35S::IPT plants (scion/rootstock) grown with 75 mM NaCl for 90 d had higher fruit trans-zeatin concentrations (1.5- to 2-fold) and yielded 30% more than WT/non-transformed plants. Enhancing root cytokinin synthesis modified both shoot hormonal and ionic status, thus ameliorating salinity-induced decreases in growth and yield.
KW - ABA
KW - cytokinins
KW - grafting
KW - IPT
KW - root zone temperature
KW - root to shoot signalling
KW - salinity
KW - Solanum lycopersicum
KW - DELAYED LEAF SENESCENCE
KW - ISOPENTENYL TRANSFERASE GENE
KW - TOBACCO PLANTS
KW - IPT GENE
KW - CUCUMBER COTYLEDONS
KW - MASS-SPECTROMETRY
KW - TRANSGENIC PLANTS
KW - HORMONAL CHANGES
KW - PLASMA-MEMBRANE
KW - SALT-TOLERANCE
UR - http://www.scopus.com/inward/record.url?scp=78649829304&partnerID=8YFLogxK
U2 - 10.1093/jxb/erq266
DO - 10.1093/jxb/erq266
M3 - Journal article
VL - 62
SP - 125
EP - 140
JO - Journal of Experimental Botany
JF - Journal of Experimental Botany
SN - 1460-2431
IS - 1
ER -