Research Focus

The regulatory mechanism of tapetum function and the role of mitochondria during pollen development

Reproductive products make up approximately 80% of world crop yield. Pollen development is usually most sensitive to abiotic stress compared to vegetative and female gametophyte development. The tapetum is essential for pollen development and provides nutrients and many components necessary for pollen growth. At the late stage, the tapetum undergoes programmed cell death (PCD) for pollen maturation. Maintaining tapetum function and precise occurrence of tapetal PCD to generate sufficient viable pollen is a crucial factor in crop yield. 

Mitochondria are critical hubs of energy, biosynthesis and signaling in plant cells. Maintaining functional mitochondria is vital for plants to adapt to abiotic stress. In cytoplasm male sterile (CMS) plants, it has been reported that mitochondrial DNA (mtDNA) rearrangement is linked to defects in tapetum function and pollen formation without affecting vegetative and female reproductive tissues. It suggests that the tapetum is sensitive to mitochondrial defects. Accordingly, we hypothesized that mitochondria play an important and unique role in the tapetum, linked to the high sensitivity of pollen development to abiotic stresses.

Our primary research interest is to elucidate the regulatory mechanism of the tapetum function and mitochondrial role in the tapetum upon developmental and environmental stimuli to accelerate crop improvements.

In early pollen development, the tapetum provides nutrients for pollen growth and secretes the enzyme to digest the callose wall of the tetrad. In addition, tapetal cells release components for exin (the outer pollen wall) formation. The tapetum further undergoes programmed cell death for pollen maturation.