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Low levels of strigolactones in roots as a component of the systemic signal of drought stress in tomato
Author(s) -
Visentin Ivan,
Vitali Marco,
Ferrero Manuela,
Zhang Yanxia,
RuyterSpira Carolien,
Novák Ondřej,
Strnad Miroslav,
Lovisolo Claudio,
Schubert Andrea,
Cardinale Francesca
Publication year - 2016
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.14190
Subject(s) - shoot , abscisic acid , rootstock , biology , acclimatization , solanum , drought stress , botany , chromosomal translocation , horticulture , gene , biochemistry
Summary Strigolactones ( SL ) contribute to drought acclimatization in shoots, because SL ‐depleted plants are hypersensitive to drought due to stomatal hyposensitivity to abscisic acid ( ABA ). However, under drought, SL biosynthesis is repressed in roots, suggesting organ specificity in their metabolism and role. Because SL can be transported acropetally, such a drop may also affect shoots, as a systemic indication of stress. We investigated this hypothesis by analysing molecularly and physiologically wild‐type ( WT ) tomato ( Solanum lycopersicum ) scions grafted onto SL ‐depleted rootstocks, compared with self‐grafted WT and SL ‐depleted genotypes, during a drought time‐course. Shoots receiving few SL from the roots behaved as if under mild stress even if irrigated. Their stomata were hypersensitive to ABA (likely via a localized enhancement of SL synthesis in shoots). Exogenous SL also enhanced stomata sensitivity to ABA . As the partial shift of SL synthesis from roots to shoots mimics what happens under drought, a reduction of root‐produced SL might represent a systemic signal unlinked from shootward ABA translocation, and sufficient to prime the plant for better stress avoidance.