Rapeseed (Brassica napus) is an important oil seed crop in the Brassicaceae family. Chemical induced male sterility (CIMS) is one of the widely used method to produce the hybrids in B. napus. Identification of the key genes and pathways that involved in CIMS were important to understand the underlying molecular mechanism. In the present report, a multi-omics integrative analysis, including of the proteomic, transcriptomic and miRNAs, combined with morphological and physiological analysis were conducted. Earlier degeneration of the tapetosomes and elaioplasts, aberrantly stacking in tapetal cells and incompletely deposition in tryphine of pollen wall were observed in chemical hybridization agent (CHA) of SX-1 treated B. napus through SEM and TEM analysis. It was revealed that the deficiencies in protein processing in endoplasmic reticulum (ER) and flavonoids biosynthesis were occurred at early stage in the SX-1 treated materials. Subsequently, plant hormone signal transduction, biosynthesis of amino acids, fatty acids and steroid in anther at later stages were identified down-regulated after SX-1 treatment. 144 transcript factors (TFs) were also indentified to down-regulated at early stage, which suggested the early regulation in anther and pollen wall development were disordered in CHA treated B. napus. In addition, 7 important miRNAs were identified and 2 of the predicted target genes of miRNAs were Rf-like genes. Taken together, an interaction network of candidate genes and the putative metabolism pathways were constructed based on the multi-omics integrative analysis, it provided a new insight into the male sterility induced by CHA of SX-1 in B. napus.

Background: Cytoplasmic male sterility (CMS) is very important in hybrid breeding. The restorer-of-fertility (Rf) nuclear genes rescue the sterile phenotype. Most of the Rf genes encode pentatricopeptide repeat (PPR) proteins. Results: We investigated the restorer-of-fertility-like (RFL) gene family in Brassica napus. A total of 53 BnRFL genes were identified. While most of the BnRFL genes were distributed on 10 of the 19 chromosomes, gene clusters were identified on chromosomes A9 and C8. The number of PPR motifs in the BnRFL proteins varied from 2 to 19, and the majority of BnRFL proteins harbored more than 10 PPR motifs. An interaction network analysis was performed to predict the interacting partners of RFL proteins. Tissue-specific expression and RNA-seq analyses between the restorer line KC01 and the sterile line Shaan2A indicated that BnRFL1, BnRFL5, BnRFL6, BnRFL8, BnRFL11, BnRFL13 and BnRFL42 located in gene clusters on chromosomes A9 and C8 were highly expressed in KC01. Conclusions: In the present study, identification and gene expression analysis of RFL gene family in the CMS system were conducted, and seven BnRFL genes were identified as candidates for the restorer genes in Shaan2A CMS. Taken together, this method might provide new insight into the study of Rf genes in other CMS systems.

The rape stem weevil (Ceutorhynchus asper Roel.) and its close relatives primarily breed on cruciferous plants and cause severe damage to rapeseed production. However, their genetic and molecular information is still scarce. Here, we generated mitogenomes for both C. asper and Ceutorhynchus albosuturalis. The lengths of the 2 mitochondrial genomes are 14,207 bp (C. asper) and 15,373 bp (C. albosuturalis), and both weevils exhibit identical numbers of protein-coding genes with the absence of trnI. A + T contents for both mitogenomes are high (80% and 79.9%, respectively). Haplotype and genetic distance analyses showed that the genetic differentiation of C. asper populations in northwestern China is low. Based on 5 datasets from mitogenomes, phylogenetic analyses with maximum-likelihood and Bayesian methods show that both species (C. asper and C. albosuturalis) fall in the CCCMS clade (Curculioninae, Conoderinae, Cossoninae, Molytinae, and Scolytinae) of Curculionidae and belong to clades H and I of the genus Ceutorhynchus, respectively. Larvae of the clade H weevils mainly are borers in petioles or stems of cruciferous plants, while larvae of the clade I weevils mainly inhabit the fruits of the same plants, suggesting that ecological niche specialization can play a critical role in the diversification of Ceutorhynchus species. This study generates baseline molecular and genetic information for future research of Ceutorhynchus-related taxa and provides insights into the phylogeny and evolution of Curculionidae.

Global warming has seriously disturbed the Earth’s ecosystems, and in this context, Asian honeybee (Apis cerana) has experienced a dramatic decline in recent decades. Here, we examined both direct and indirect effects of climate change on A. cerana through ecological niche modeling of A. cerana, and its disease pathogens (i.e., Chinese sacbrood virus and Melissococcus plutonius) and enemies (i.e., Galleria mellonella and Vespa mandarinia). Ecological niche modeling predicts that climate change will increase the potential suitability of A. cerana, but it will also cause some of the original habitat areas to become unsuitable. Outbreak risks of Chinese sacbrood disease and European Foulbrood will increase dramatically, while those of G. mellonella and V. mandarinia will decrease only slightly. Thus, climate change will produce an unfavorable situation for even maintaining some A. cerana populations in China in the future. Genetic structure analyses showed that the A. cerana population from Hainan Island had significant genetic differentiation from that of the mainland, and there was almost no gene flow between the 2, suggesting that urgent measures are needed to protect the unique genetic resources there. Through taking an integrated planning technique with the Marxan approach, we optimized conservation planning, and identified potential nature reserves (mainly in western Sichuan and southern Tibet) for conservation of A. cerana populations. Our results can provide insights into the potential impact of climate change on A. cerana, and will help to promote the conservation of the keystone honeybee in China and the long-term sustainability of its ecosystem services.