Characterization and expression profiling of cucumber kinesin genes during early fruit development: revealing the roles of kinesins in exponential cell production and enlargement in cucumber fruit

Xue Yong Yang,Wei Jie Jiang,San Wen Huang,Xiao Ling Liu,Yan Wang,Hong Jun Yu,Xiao Meng Zhang,Guo Qin Liu

doi:10.1093/jxb/ert269

Abstract

Rapid cell division and expansion in early fruit development are important phases for cucumber fruit yield and quality. Kinesin proteins are microtubule-based motors responsible for modulating cell division and enlargement. In this work, the candidate kinesin genes involved in rapid cell division and expansion during cucumber fruit development were investigated. The morphological and cellular changes during early fruit development were compared in four cucumber genotypes with varied fruit size. The correlation between the expression profiles of cucumber kinesin genes and cellular changes in fruit was investigated. Finally, the biochemical characteristics and subcellular localizations of three candidate kinesins were studied. The results clarified the morphological and cellular changes during early cucumber fruit development. This study found that CsKF2–CsKF6 were positively correlated with rapid cell production; CsKF1 and CsKF7 showed a strongly positive correlation with rapid cell expansion. The results also indicated that CsKF1 localized to the plasma membrane of fast-expanding fruit cells, that CsKF2 might play a role in fruit chloroplast division, and that CsKF3 is involved in the function or formation of phragmoplasts in fruit telophase cells. The results strongly suggest that specific fruit-enriched kinesins are specialized in their functions in rapid cell division and expansion during cucumber fruit development.

Highlights

In most plants, early fruit development can be divided into three phases: development of the ovary, cell division, and subsequent cell expansion (Gillaspy et al, 1993)
The results indicated that CsKF1 localized to the plasma membrane of fast-expanding fruit cells, that CsKF2 might play a role in fruit chloroplast division, and that CsKF3 is involved in the function or formation of phragmoplasts in fruit telophase cells
After 16 days after anthesis (DAA), 9930 fruit showed no significant morphological changes. These results indicated that the period from 3 DAA to 5 DAA was an obvious boundary for fast growth of the fruit of 9930

Summary

Introduction

Early fruit development can be divided into three phases: development of the ovary, cell division, and subsequent cell expansion (Gillaspy et al, 1993). The rapid cell division and expansion in early fruit development are important phases for cucumber fruit production. In addition to the crucial roles in fruit size, shape, and yield, recent research has shown that the early stage is an important determinant of fruit quality traits, such as the. Transcriptome analyses have indicated that complicated factors are involved in early cucumber fruit growth, and cytoskeletal proteins are suggested to play important roles in this process (Ando et al, 2012)

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Results

Conclusion