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The tomato CAROTENOID CLEAVAGE DIOXYGENASE 8 ( S l CCD 8 ) regulates rhizosphere signaling, plant architecture and affects reproductive development through strigolactone biosynthesis
Author(s) -
Kohlen Wouter,
Charnikhova Tatsiana,
Lammers Michiel,
Pollina Tobia,
Tóth Peter,
Haider Imran,
Pozo María J.,
Maagd Ruud A.,
RuyterSpira Carolien,
Bouwmeester Harro J.,
LópezRáez Juan A.
Publication year - 2012
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/j.1469-8137.2012.04265.x
Subject(s) - strigolactone , rhizosphere , biology , solanum , orobanchaceae , shoot , botany , symbiosis , microbiology and biotechnology , arabidopsis , biochemistry , gene , mutant , bacteria , genetics
Summary Strigolactones are plant hormones that regulate both above‐ and belowground plant architecture. Strigolactones were initially identified as rhizosphere signaling molecules. In the present work, the tomato ( Solanum lycopersicum ) CAROTENOID CLEAVAGE DIOXYGENASE 8 ( S l CCD 8 ) was cloned and its role in rhizosphere signaling and plant physiology assessed by generating knock‐down lines. Transgenic S l CCD 8 plants were generated by RNA i‐mediated silencing. Lines with different levels of strigolactone reduction – confirmed by UPLC ‐ MS / MS – were selected and their phenotypes investigated. Lines exhibiting reduced Sl CCD 8 levels displayed increased shoot branching, reduced plant height, increased number of nodes and excessive adventitious root development. In addition, these lines exhibited reproductive phenotypes such as smaller flowers, fruits, as well as fewer and smaller seeds per fruit. Furthermore, we show that strigolactone loading to the xylem sap is possibly restricted to orobanchol. Infestation by Phelipanche ramosa was reduced by 90% in lines with a relatively mild reduction in strigolactone biosynthesis and secretion while arbuscular mycorrhizal symbiosis, apical dominance and fruit yield were only mildly affected. This demonstrates that reduction of strigolactone biosynthesis could be a suitable tool in parasitic weed management. Furthermore, our results suggest that strigolactones are involved in even more physiological processes than so far assumed.