Light is one of the most important factor influencing plant growth and development all through their life cycle. One of the well-known light-regulated processes is de-etiolation, i.e. the switch from skotomorphogenesis to photomorphogenesis. The hormones cytokinins (CKs) play an important role during the establishment of photomorphogenesis as exogenous CKs induced photomorphogenesis of dark-grown seedlings. Most of the studies are conducted on the plant model Arabidopsis, but no or few information are available for important crop species, such as tomato (Solanum lycopersicum L.). In our study, we analyzed for the first time the endogenous CKs content in tomato hypocotyls during skotomorphogenesis, photomorphogenesis and de-etiolation. For this purpose, two tomato genotypes were used: cv. Rutgers (wild-type; WT) and its corresponding mutant (7B-1) affected in its responses to blue light (BL). Using physiological and molecular approaches, we identified that the skotomorphogenesis is characterized by an endoreduplication-mediated cell expansion, which is inhibited upon BL exposure as seen by the accumulation of trancripts encoding CycD3, key regulators of the cell cycle. Our study showed for the first time that iP (isopentenyladenine) is the CK accumulated in the tomato hypocotyl upon BL exposure, suggesting its specific role in photomorphogenesis. This result was supported by physiological experiments and gene expression data. We propose a common model to explain the role and the relationship between CKs, namely iP, and endoreduplication during de-etiolation and photomorphogenesis.

• MeSH
• buněčný cyklus účinky léků   genetika   MeSH
• cyklin D3 genetika   metabolismus   MeSH
• cytokininy metabolismus   MeSH
• endoreduplikace fyziologie   účinky záření   MeSH
• fylogeneze MeSH
• hypokotyl fyziologie   účinky záření   MeSH
• isopentenyladenosin metabolismus   MeSH
• morfogeneze fyziologie   účinky záření   MeSH
• ploidie MeSH
• rostlinné proteiny genetika   metabolismus   MeSH
• semenáček fyziologie   účinky záření   MeSH
• Solanum lycopersicum fyziologie   účinky záření   MeSH
• světlo MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• cyklin D3 MeSH
• cytokininy MeSH
• isopentenyladenosin MeSH
• N(6)-(delta(2)-isopentenyl)adenine MeSH Prohlížeč
• rostlinné proteiny MeSH