Expression Analysis and Interaction Protein Screening of CoZTL in Camellia oleifera Abel

Abstract

Camellia oleifera Abel., which produces fruits of high comprehensive utilization value, is an important woody oil tree in China. ZEITLUPE (ZTL) is a blue light receptor and clock component protein that is involved in various physiological and biochemical processes. However, the expression pattern and function of C. oleifera ZTL (CoZTL) remain unclear. In this study, the coding sequence of the CoZTL gene was isolated and the protein function was explored using bioinformatics and expression analyses and heterologous expression techniques. The results showed that the CoZTL protein was highly conserved during evolution and was on the same branch of the evolutionary tree as the ZTL proteins from Ipomoea nil and Nicotiana attenuata. CoZTL was mainly expressed in the fruit shells and stems of C. oleifera, and its expression level fluctuated greatly during flower bud development. Transgenic CoZTL-overexpressing Arabidopsis plants showed delayed flowering under long-day conditions as well as light-dependent promotion of hypocotyl elongation. Furthermore, yeast two-hybrid library screening revealed that seven C. oleifera proteins (CoAAT, Coβ-GAL, CoLAT52-like, CoCAR4-like, CoAO, CoUQCC1, and CoADF 2) interacted with CoZTL. Our results indicate that CoZTL plays an important role in C. oleifera flowering and hypocotyl growth.