Sclerotinia sclerotiorum, a worldwide distributed fungal pathogen, causes serious adverse effects on the yield and seed quality of rapeseed. Polygalacturonase-inhibiting proteins (PGIPs) can protect the cell wall from degradation by pathogen-secreted polygalacturonases (PGs). The present study found several PGIPs from Oryza sativa, especially OsPGIP6 and 3 have much higher inhibitory activities to SsPGs than BnPGIP2 from Brassica napus. Among them, OsPGIP1, 4, 6 can significantly elevate the resistance of transgenic Arabidopsis to S. sclerotiorum. Subsequently, OsPGIP1, 3, 4, 6 were subjected to SSR resistance assay in transgenic rapeseed plants. Among which, OsPGIP6 showed the highest resistance to S. sclerotiorum. At 48 h after detached leaves inoculation, the lesion area of OE-OsPGIP6 rapeseed plants is only 17.93% of the non-transgenic line, and 22.17, 21.32, 52.78, 56.47%, compared to OE-BnPGIP2, OE-OsPGIP1, OE-OsPGIP2, OE-OsPGIP4, respectively. Furthermore, the lesion area of OE-OsPGIP6 reached 10.11% compared to WT at 72 hpi. Also, the lesion length on the stem of OE-OsPGIP6 plants was reduced by 36.83% compared to WT. These results reveal that OsPGIP family, especially OsPGIP6, has a great potential in rapeseed S. sclerotiorum-resistance breeding.
Table S6. GO enrichment in molecular function (MF) category of the genes. (XLSX 50 kb)
Table S5. GO enrichment in cellular components (CC) category of the genes. (XLSX 26 kb)
To reveal the comprehensive mechanism which is associated with the biosynthesis of volatile compounds and the accompanying texture change, RNA-seq was employed to survey the differentially expressed genes (DEGs), at the transcriptional level, of one cultivar at three stages of ripening and of four melting peach cultivars at harvest stage. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that highly ranked genes are involved in “Ribosome” and “Plant-pathogen interaction,” “Flavonoid biosynthesis,” “Linoleic acid metabolism,” and “Flavone and flavonol biosynthesis” during the fruit-ripening process. The quantitative real-time PCR (qRT-PCR) validation with 15 aroma and softening-related genes showed high correlation with the RNA-seq results. Transcripts of a nonspecific lipid transfer protein (nsLTP, ppa013554) and an ATP-binding cassette transporter (ABC, ppa002351) increased from the early ripening stage to the commercial harvest stage and then declined in the fully ripening stage. The highest transcript abundance was in the aroma-enriched cv. “Hu Jing Mi Lu” (HJ) and lowest in the cv. “Zhong Hua Shou Tao” with slight aroma. Fifty gene families related to the formation of aroma compounds were found. For peach lactone biosynthesis, we inferred that ppa002510 and ppa002282 may be the two important acyl-CoA oxidase genes correlating with the difference in γ-decalactone concentrations among the four cultivars. The expression of one 3-hydroxyacyl-CoA dehydrogenase gene (HCAD, ppa008854) was upregulated during ripening. Thirteen gene families were associated to fruit softening. Four aquaporin (AQP) genes showed cultivar-specificity for HJ, and one of them, ppa009506, reached maximum accumulation of transcripts at harvest stage. The batch of novel genes (nsLTP, ACX, AOC, ABC, HCAD, AQP) found here facilitates understanding of the molecular mechanism of melting peach aroma biosynthesis and fruit softening.
There are approximately 100 species and 10,000 cultivars of Lilium and in general their phylogeny is understood. Difficulties remain, however, in understanding the breeding relationships of cultivars and commercial hybrids. One solution to this problem is to identify a selection of validated and transferable SSR markers for use in genotyping. Although over 100 Lilium SSRs have been developed, they have not been validated for use with broad populations. Here, were-evaluated 112 SSRs with 69 lily accessions from different sources, and selected 70 SSRs as easy to score, transferable and polymorphic in all accessions tested. Based on the marker data from 70 SSRs, two main clusters were established for 69 accessions using TREECON, one includes Asiatic hybrids, Longiflorum x Asiatic hybrids and Asiatic local landraces (Mum brownii, L. brownii var. giganteum, Lilium pumilum, Lilium davidii var. unicolor and Lilium lancifolium), the other is composed primarily of Oriental hybrids and Oriental x Trumpet hybrids, which is in agreement with previous studies and the breeding pedigree. The utility of the 70 SSR markers for establishing parentage and taxon identity of landraces was validated. Our study offers valuable information and validated markers for Lilium systematic classification and the establishment of identity. (C) 2015 Elsevier Ltd. All rights reserved.