Anatomy and transcript profiling of gynoecium development in female sterile Brassica napus mediated by one alien chromosome from Orychophragmus violaceus

Abstract

BackgroundThe gynoecium is one of the most complex organs of angiosperms specialized for seed production and dispersal, but only several genes important for ovule or embryo sac development were identified by using female sterile mutants. The female sterility in oilseed rape (Brassica napus) was before found to be related with one alien chromosome from another crucifer Orychophragmus violaceus. Herein, the developmental anatomy and comparative transcript profiling (RNA-seq) for the female sterility were performed to reveal the genes and possible metabolic pathways behind the formation of the damaged gynoecium.ResultsThe ovules in the female sterile Brassica napus with two copies of the alien chromosomes (S1) initiated only one short integument primordium which underwent no further development and the female gametophyte development was blocked after the tetrad stage but before megagametogenesis initiation. Using Brassica_ 95k_ unigene as the reference genome, a total of 28,065 and 27,653 unigenes were identified to be transcribed in S1 and donor B. napus (H3), respectively. Further comparison of the transcript abundance between S1 and H3 revealed that 4540 unigenes showed more than two fold expression differences. Gene ontology and pathway enrichment analysis of the Differentially Expressed Genes (DEGs) showed that a number of important genes and metabolism pathways were involved in the development of gynoecium, embryo sac, ovule, integuments as well as the interactions between pollen and pistil.ConclusionsDEGs for the ovule development were detected to function in the metabolism pathways regulating brassinosteroid (BR) biosynthesis, adaxial/abaxial axis specification, auxin transport and signaling. A model was proposed to show the possible roles and interactions of these pathways for the sterile gynoecium development. The results provided new information for the molecular mechanisms behind the gynoecium development at early stage in B. napus.

Comparative transcriptome analyses of deltamethrin-susceptible and -resistant Culex pipiens pallens by RNA-seq

“…In our results, the percentages of alignment rate (Table 1) and gene coverage (Fig. 1) agreed with the RNA-seq results of other species (Fu et al 2014; Peng et al 2013; Wang et al 2013; Zhang et al 2013), indicating the feasibility of the alignment method in our study.…”

Genome-wide transcriptome analysis of female-sterile rice ovule shed light on its abortive mechanism

“…In our data, many genes belonging to these TF families, such as two YABBY gene family members (LOC_Os03g11600 and LOC_Os07g06620), two HD-Zip III family genes (OSHB3 and OSHB4), an ARF gene family gene (ARF6), and a KANADI family gene (KANADI4), were significantly differentially expressed between the ovules of two rice lines at stages 1 and 2. This finding is consistent with the previous observation that there were obvious differences in adaxial/abaxial polarity-related TF gene expression between the wild-type and female sterile Brassica napus (Fu et al 2014). Therefore, our results suggest that the adaxial/abaxial polarity-related TF genes may contribute to the fertile female gametophyte formation in rice.…”

Production of red‐flowered oilseed rape via the ectopic expression of Orychophragmus violaceus OvPAP2

“…qRT-PCR assays with three replicates were performed using a KAPA SYBR FAST qPCR kit (Kapa Biosystems, Boston, MA) on a Bio-Rad CFX96 Real-Time Detection System. The Bnaactin3 gene was used as an internal control for data normalization, and quantitative variation in the different replicates was calculated using the delta-delta threshold cycle relative quantification method as described previously (Fu et al, 2014).…”