| The regulation of fruit development and ripening is one of the core question in pomology. For many years, a large number of researches were carried out around fruit development regulation mechanisms. It’s still unclear about the intermal mechanisms, because most researches were confined to the morphological anatomical and physiological and biochemical changes during fruit development. With the rapid development of molecular biology and cell biology research, people gradually realize that the basis of metabolic regulation is cell signaling transduction, and protein phosphorylations play a key role. Strawberry is a typical non-climacteric fruit, in recent years, it has become one of the model materials in fruit development researches. This paper used strawberry (Fragaria×ananassa) as test materials, studied the regulation mechanisms of strawberry fruit development and ripening, from the point of view in cell signal transduction, the main results were as follows:1. This reasearch found the Sucrose Nonfermenting Protein Kinase2s (FaSnRK2s) is made up of nine members in strawberry genome based on bioinformatics analysis. Through the spatio-temporal gene expression analysis of FaSnRK2s, we found there was a close relationship between FaSnRK2.6gene expression and fruit development process:the gene expression of FaSnRK2.6fell sharply during fruit development. The gene expression of FaSnRK2.6was regulated not only by ABA, but also by the temperature. The ABA and temperature have been confirmed as the internal and external signal (factors) manipulated fruit ripening. These suggest that FaSnRK2.6may play an important role in strawberry fruit development and ripening. Protein sequence alignment analysis found that FaSnRK2.6and Open Stomata1(OST1) were orthologous proteins. OST1is the core signaling protein in the manipulation of stomatal movement, stomatal movement and strawberry fruit development may have a similar mechanism of signal transduction. Using transient gene manipulation techniques, over-expression FaSnRK2.6can delay the process of fruit development, instead RNAi FaSnRK2.6can promote the process of fruit development. Manipulation the gene expressiong of FaSnRK2.6can affect a series ripening-related parameters and gene expression, such as pigment metabolism, cell wall metabolism and aroma. Further analysis showed that there were physical interactions between FaSnRK2.6and ABA downstream signal FaABI1. These results suggest that FaSnRK2.6is a negative regulatory in strawberry fruit development and ripening.2. High/low temperatures can accelerate/delay the strawberry fruit development process, suggest that the temperature stress response signal system play an important role during the process. This study found that, high/low temperatures can restrain/maintain FaSnRK2.6expression respectively; At the same time, manipulated FaSnRK2.6expression can influence the expression of a series of temperature response genes. FaSnRK2.6is an important signal molecule during the process of fruit development under temperature control, and mediated the strawberry fruit development and ripening induced by temperature stress for adversity stress adaptation.3. For reveal the signal transduction mechanism of FaSnRK2.6further, the protein interactions of FaSnRK2.6have been analyzed, and found there were all physical interactions between FaSnRK2.6and FaMPK3/FaMPK4/FaMPK6(three numbers of Mitogen Activated Protein Kinase, MPKs). These suggest that these signal proteins may play important roles in strawberry fruit development and ripening. Further tests found that, manipulations of FaMPK3expression can affect fruit development process, indicated FaMPK3is one of the important regulatory factors in strawberry fruit development. We found there were physical interactions between FaMPK3and FaMYB10using the yeast two hybrid assay and BiFC assay. Researches have shown that FaMYB10can regulate strawberry fruit coloring, suggests that FaMPK3may involved in fruit coloring process through regulating FaMYB10.To sum up, this research proved FaSnRK2.6was a negative regulatory factor in strawberry fruit development and ripening. FaSnRK2.6can also mediate the temperature stress to realize stress adaptation through regulated fruit ripening. FaMPK3involved in regulation of fruit development, and may regulate fruit coloring through manipulated transcription factor FaMYB10.This research found a possible signaling pathway that may regulate strawberry fruit coloring: ABA/FaPYRl/FaABI1/FaSnRK2.6/FaMPK3/FaMYB10/fruit coloring... |
PDF Full Text Request