Cytokinin-induced parthenocarpic fruit development in tomato is partly dependent on enhanced gibberellin and auxin biosynthesis.
Fruit set of plants largely depends on the biosynthesis and crosstalk of phytohormones. To date the role of cytokinins (CKs) in the fruit development is less understood. Here, we showed that parthenocarpic fruit could be induced by 1-(2-chloro-4-pyridyl)-3-phenylurea (CPPU, an active CK) in tomato (Solanumlycopersicum cv. Micro-Tom). The fresh weight of CPPU-induced parthenocarpic fruits was comparable with that induced by GA3. Importantly, CPPU-induced parthenocarpy was found to be compromised by simultaneous application of paclobutrazol (a GA biosynthesis inhibitor), and this effect could be restored by exogenous GA3. Like pollination, CPPU-induced fruit showed enhanced accumulation of GA1+3 and indole-3-acetic (IAA), which were accompanied by elevated expression of GA biosynthesis genes like SlGPS, SlGA20ox1, SlGA20ox2 and SlGA3ox1, and IAA biosynthesis gene ToFZY. Elevated GAs level in CPPU-induced fruits was also associated with down-regulation of GA inactivation genes, namely SlGA2ox1,2,3,4,5 in comparison with untreated control. These results suggested that CKs may induce parthenocarpy in tomato partially through modulation of GA and IAA metabolisms.
Department of Horticulture, Zhejiang University, Hangzhou, People's Republic of China.
Jiangang
J
Ding
Biwei
B
Chen
Xiaojian
X
Xia
Weihua
W
Mao
Kai
K
Shi
Yanhong
Y
Zhou
Jingquan
J
Yu
D003583:Cytokinins / Q000494:pharmacology*; D005638:Fruit / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism*; D005875:Gibberellins / Q000378:metabolism*; D007210:Indoleacetic Acids / Q000378:metabolism*; D018551:Solanum lycopersicum / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism*; D011092:Polyethylene Glycols / Q000494:pharmacology; D011140:Polyurethanes / Q000494:pharmacology; D044004:Xanthones / Q000494:pharmacology
D003583:Cytokinins; C540014:GA3 compound; D005875:Gibberellins; D007210:Indoleacetic Acids; D011140:Polyurethanes; D044004:Xanthones; C030554:co(polyether)polyurethane; D011092:Polyethylene Glycols; C030737:indoleacetic acid