Comparative cytological and transcriptome analyses of mutant delayed degeneration of tapetal cells and promotes abnormal microspore development in neo-tetraploid rice.

We aimed to investigate the genetic defects related to pollen development and infertility in , a novel tetraploid rice germplasm known as Neo-tetraploid rice. This rice variety was created through the crossbreeding and selective breeding of various autotetraploid rice lines and has previously shown high fertility. Our previous research has revealed that the gene, encoding a eukaryotic translation initiation factor 3 subunit E, regulates pollen fertility. However, the underlying mechanism behind this fertility is yet to be understood. To shed light on this matter, we performed a combined cytological and transcriptome analysis of the gene. Cytological analysis indicated that underwent abnormal tapetal cells, microspore, and middle layer development, which led to pollen abortion and ultimately to male sterility. Genetic analysis revealed that the F plants showed normal fertility and an obvious advantage for seed setting compared to . Global gene expression analysis in revealed a total of 7545 genes were detected at the meiosis stage, and 3925 and 3620 displayed upregulation and downregulation, respectively. The genes were significantly enriched for the gene ontology (GO) term "carbohydrate metabolic process. Moreover, 9 genes related to tapetum or pollen fertility showed down-regulation, such as (ATP Binding Cassette G26), (Thermosensitive Male Sterility), (Programmed cell death regulatory), (Kinesin Motor), (Metallothionein), and (Atypical strictosidine synthase), which were validated by qRT-PCR. Further analyses of DEGs identified nine down-regulated transcription factor genes related to pollen development. is an important regulator of the development of tapetum and microspore. The regulatory gene network described in this study may offer important understandings into the molecular processes that underlie fertility control in tetraploid rice.