However, genes involved in the VLC alkane biosynthesis in rice remain unclear, and the alkane-form pathway in rice has still to be further explored. OsCER1 was highly expressed in the tapetum stage 10 and bicellular pollen cells stage Downregulation of OsCER1 in rice led to sterility, and fewer amyloplasts within the mature pollen grains. In addition, the downregulation of OsCER1 in rice caused delayed tapetal programmed cell death and abnormal development of plastids in the tapetal cells.
Furthermore, significantly altered levels of expression of genes involved in the pollen development were exhibited in the OsCER1 knocked down plants. This work provides insights into the VLC alkanes biosynthesis in anther development in rice. Keywords: Oryza sativa L. Rice Oryza sativa L. Abnormal reproductive development has significantly influenced rice production. Rice anthers have four lobes in which the primordial cells differentiate into reproductive pollen mother cells.
Four somatic cell layers surround these cells: the tapetum, the middle layer, the endothecium, and the epidermis, which are arranged from the innermost to the outermost layer Goldberger et al. Covering the epidermal cells, the rice anther has a reticulate cuticle, which plays a protective role in pollen development Li and Zhang, The anther cuticle is a thin, continuous hydrophobic layer that coats the outermost surface of anthers and is mainly composed of epicuticular waxes and a cutin matrix Kunst and Samuels, ; Jung et al.
Cuticular waxes are mostly composed of very-long-chain fatty acids VLCFAs derivatives, including primary and secondary alcohols, aldehydes, alkanes, ketones, and esters Kunst and Samuels, ; Buschhaus and Jetter, Abnormal cuticular waxes of anthers frequently accompany aborted pollen development Jung et al.
The majority of long-chain fatty acids LCFAs serve as central intermediates in catalytic steps, such as elongation and acyl editing Haslam and Kunst, , and some LCFAs remain in plastids integrated into polar lipids, such as glycolipids and phospholipids Li-Beisson et al. Subsequently, extended VLCFAs are modified into diverse VLCFAs derivatives, the main components of wax, via two pathways, namely, the alcohol-forming acyl reduction pathway and the alkane-forming decarbonylation pathway.
