ZmSTK1 and ZmSTK2, encoding receptor‐like cytoplasmic kinase, are involved in maize pollen development with additive effect

Abstract

SummaryPollen germination and pollen tube growth are important physiological processes of sexual reproduction of plants and also are involved in signal transduction. Our previous study reveals that ZmSTK1 and ZmSTK2 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. Here, we report that ZmSTK1 and ZmSTK2, expressed at late stages of pollen development, regulate maize pollen development with additive effect. ZmSTK1 or ZmSTK2 mutation exhibited severe pollen transmission deficiency, which thus influenced pollen fertility. Moreover, the kinase domains of ZmSTKs were cross‐interacted with C‐terminus of enolases detected by co‐immunoprecipitation (Co‐IP) and yeast two‐hybrid system (Y2H), respectively. Further, the detective ZmSTK1 or ZmSTK2 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. This study reveals that ZmSTK1 and ZmSTK2 regulate maize pollen development and indirectly participate in glycolytic pathway.

Identification of fertility-related genes for maize CMS-S via Bulked Segregant RNA-Seq

“…Protein kinases play roles in signal transduction. Mutants of two receptor-like cytoplasmic kinases (RLCK) in maize, ZmSTK1 or ZmSTK2, exhibited severe pollen transmission deficiency and fertility ( Fan et al, 2018 ). In Arabidopsis , suppression of ASK β (AtSK32), a Clade III Arabidopsis GSK3, leaded to pollen defect during late pollen development ( Dong et al, 2015 ).…”

Receptor‐like kinases and their signaling cascades for plant male fertility: loyal messengers

“…3a) (Liu et al ., 2021b; Huang et al ., 2023). Maize serine/threonine kinase 1/2 (ZmSTK1/2) also participate in pollen germination by assuring the activity of enolase1/2 (ZmEno1/2) in mature pollen grains (Fan et al ., 2018).…”

Receptor Kinases: A Sophisticate Protein Network to Maintain Plant life Continuity. An Update

“…During pollen production there are many genes, which code specific proteins and enzyme kinases responsible for health and viability of pollens during pollination until fertilization [37,85]. Some genes only express during specific times of plant development such as in maize ZmSTK gene family coding for serine/threonine enzyme kinase express only during pollen formation and its mutation causes severe protein disruption in pollen development [86]. Gene ontology (GO) functions and molecular analysis show that ZmSTK1 & ZmSTK2 mutant paralogs are expressed in pollen development and germination and cause damage during pollen transmission.…”

“…Gene ontology (GO) functions and molecular analysis show that ZmSTK1 & ZmSTK2 mutant paralogs are expressed in pollen development and germination and cause damage during pollen transmission. Zmstk1 single mutant causes less damage as compared to double mutant and zmstk2 even has less effect on pollen damage but when both zmstk1 & zmstk2 combine, zmstk2 acts as enhancer of zmstk1 expression and damage is so severe that double mutant pollens cannot survive for fertilization and likely, no seeds are formed in offspring [86][87][88][89].…”