Pollen development involves regulation of numbers of proteins and signalling molecules (Beale and Johnson, 2013 Chen et al., 2014). While the two smaller sperm cells participate in the double fertilization and finally produce zygote, endosperm and seed tissues, the vegetative cell provides nutrition for pollen germination and pollen tube elongation. In Zea mays, mature microspores/pollens emerge after meiosis followed by two cycles of mitosis and consist of two sperm cells and one vegetative cell. Two distinct and successive developmental phases, microsporogenesis and microgametogenesis, lead to the production of mature pollen grains. Pollen development is a complex and highly coordinated biological process. This study reveals that Zm STK1 and Zm STK2 regulate maize pollen development and indirectly participate in glycolytic pathway. Further, the detective Zm STK1 or Zm STK2 was associated with decreased activity of enolases and also reduced downstream metabolite contents, which enolases are involved in glycolytic pathway, such as phosphoenolpyruvate ( PEP), pyruvate, ADP/ ATP, starch, glucose, sucrose and fructose. Moreover, the kinase domains of Zm STKs were cross‐interacted with C‐terminus of enolases detected by co‐immunoprecipitation (Co‐ IP) and yeast two‐hybrid system (Y2H), respectively. Zm STK1 or Zm STK2 mutation exhibited severe pollen transmission deficiency, which thus influenced pollen fertility. Here, we report that Zm STK1 and Zm STK2, expressed at late stages of pollen development, regulate maize pollen development with additive effect. Our previous study reveals that Zm STK1 and Zm STK2 are two receptor‐like cytoplasmic kinases ( RLCK) homologs in Zea mays as members of receptor‐like protein kinase ( RLK) subfamily, sharing 86% identity at the amino acid level.

Pollen germination and pollen tube growth are important physiological processes of sexual reproduction of plants and also are involved in signal transduction.

Nelson Model 8908 Manual