Abstract
Female sterility is a common phenomenon in the plant world, and systematic research has not been carried out in gymnosperms. In this study, the ovules of No. 28 sterile line and No. 15 fertile line Pinus tabuliformis were used as materials, and a total of 18 cDNA libraries were sequenced by the HiSeqTM 4000 platform to analyze the differentially expressed genes (DEGs) and simple sequence repeats (SSRs) between the two lines. In addition, this study further analyzed the DEGs involved in the signal transduction of plant hormones, revealing that the signal pathways related to auxin, cytokinin, and gibberellin were blocked in the sterile ovule. Additionally, real-time fluorescent quantitative PCR verified that the expression trend of DEGs related to plant hormones was consistent with the results of high-throughput sequencing. Frozen sections and fluorescence in situ hybridization (FISH) were used to study the temporal and spatial expression patterns of PtRab in the ovules of P. tabuliformis. It was found that PtRab was significantly expressed in female gametophytes and rarely expressed in the surrounding diploid tissues. This study further explained the molecular regulation mechanism of female sterility in P. tabuliformis, preliminarily mining the key factors of ovule abortion in gymnosperms at the transcriptional level.
Highlights
Sexual reproduction is the most evolved reproductive mode of plants
The free nuclei were still increased in fertile line (FER); this trend was arrested in sterile line (STE)
We found that differentially expressed genes (DEGs) related to hormones were highly expressed in FER, and the expression levels of SAUR and DELLA were significantly high in the FNM2 stage
Summary
The development of embryos and reproductive organs is the key step to completing sexual reproduction. In the plant kingdom, female sterility is widespread during sexual reproduction, which might be induced by incomplete megagametophyte development, abnormal ovule development, the wrong number of polar nuclei, meiosis mitotic disorder, and some other factors. Awasthi et al found that the number of polar nuclei in megagametophytes was reduced in rice, and the unusual cell cycle progression caused disordered mitotic division during the formation of ovules [3]. These results showed that the mechanism of female sterility in plants is complicated. Revealing the molecular regulation mechanism of female sterility is of great significance for the improvement of germplasm resources and the breeding of plus trees
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
