The density of oil gland is an important factor to determine the content of essential oil in citrus. To understand the genetic control of oil gland development，a segregation population of 159 F1 individuals was constructed by crossing Luowen kumquat[Fortunella japonica（Thunb.）Swingle]with Huapi kumquat（F. crassifolia Swingle‘Huapi’），a low oil gland density mutation variety. Thirty individuals of each extreme phenotype group with either high-density or low-density oil glands were chosen and their DNA were pooled to construct two DNA pools for genomic re-sequencing to identify candidate genes associated with oil gland development. The results of Bulked Segregant Analysis（BSA）indicated that the 25 980 001–29 160 001 bp region of chromosome 9 is highly correlated to the density of oil glands. Through analysis of recombination frequency of SNP，511 SNP loci distributed in 301 genes were found to be possibly associated with the density of oil glands. The homology function analysis suggested that 11 of these genes（Ciclev10005243m.g，Ciclev10005288m.g，Ciclev10005338m.g，Ciclev10005441m.g，Ciclev10006448m.g，Ciclev10005804m.g，Ciclev10004719m.g，Ciclev10005888m.g，Ciclev10006502m.g，Ciclev10005197m.g and Ciclev10004431m.g）involving in cell programmed death，the function and construction of cell wall，and cell elongation and expansion may be the important genetic factors controlling the development of oil gland.
In order to further understand the molecular mechanism of GLV peptide in peach fruit ripening and softening，the PpRGI gene family was identified in peach genome, and its expression levels during fruit development in melting flesh and stony hard peach were detected by qRT-PCR. Additionally，we also used qRT-PCR to detect the expression level of PpRGI gene family in stony-hard peach fruit under NAA treatment，and in peach callus under exogenous peptide treatment. The results showed that 6 PpRGI candidate genes were found in the peach genome. The PpRGI contained the LRR conserved domain and signal peptide at the N-terminus. The phylogenetic analysis revealed that PpRGI gene family was divided into 2 groups. Expression analysis showed that PpRGI1，PpRGI3 and PpRGI4 were expressed in different tissues of melting-flesh peach and their expression levels in melting-flesh peach fruits were higher than in stony-hard peach fruits. PpRGI1 has the highest expression in different peach types and the expression of PpRGI1 was increased under NAA and peptide treatment. These results suggested that the PpRGI gene family members are highly and structurally conserved and PpRGI1 may be involved in the biosignaling pathway of peach peptide hormones.
To investigate the function of microRNA171（miR171）in cucumber，four precursors Csa-miR171a，Csa-miR171b，Csa-miR171c，Csa-miR171d of Csa-miR171 family genes were cloned in the northern Chinese cucumber‘Beijingjietou’and followed by sequence alignment and phylogenetic analysis. Target genes of the mature sequence of Csa-miR171 were predicted and functional analysis was performed in Arabidopsis by genetic transformation. The results showed that the two mature sequences，Csa-miR171a and Csa-miR171b were cleaved from the four Csa-miR171 precursors. Phylogenetic analysis showed that Csa-miR171a，Csa-miR171b，Csa-miR171c，Csa-miR171d were closer to Cme-miR171e，Cme-miR171c，Cme-miR171a，Cme-miR171b in melon than those in Arabidopsis，rice and tomato，etc. GRAS transcription factor family was predicted to be the main target gene of Csa-miR171. Overexpression of Csa-miR171a in Arabidopsis significantly affected the phenotypes including leaf morphology and leaf color，blooming time，root，fruit and floral morphology.
In this study，a new type of disease-resistant activator named BDO-1，（E）-N-[2-fluoro-4-（trifluoromethyl）styryl]-1-met-hyl-1H-pyrazolo[3,4-d]pyrimidin-4-amine，which belongs to pyrazolium pyrimidine derivative was reported and studied. To reveal the resistance mechanism of BDO-1，the induced resistance effect of the activator to cucumber against Fusarium oxysporum f. sp. cucumerinum was investigated. The antifungal activity of BDO-1 was detected by using plate growth rate method，and the result showed that BDO-1 had no antagonistic effect against F. oxysporum. The leaves were treated with 10 mg · L-1 BOD-1 by foliar spraying method at two-leaf and one-hearted cucumber stage. A total of five times were induced in 25 days and the pathogen F. oxysporum was inoculated after 24 h of last induction.The induced assay results indicated that the induced resistance effect of BDO-1 to cucumber against F. oxysporum was 53.28%. In addition，laser confocal microscopy confirmed that the infection rates of F. oxysporum on cucumber were inhibited by induction of BDO-1. Meanwhile，fluorescence microscopy showed that the secondary metabolite callose accumulated in cucumber plants on the 3rd day post-inoculation，and the highest content of anti-oxidant H2O2 appeared in cucumber plants on the 1st day post-inoculation. Besides，qRT-PCR revealed that BDO-1 could induce expression of six disease-resistant defense genes. After BDO-1 induction，the expression levels of CAT，PAL，LOX and EIN2 in the defense genes of root defense tissues increased significantly from 1st day to 7th day post-inoculation，and the expression levels of PR1 and SOD were higher at 1st day post-inoculation，significantly reduced in 3rd day and 7th day post-inoculation. This study provides an insight and basis for the development and application of BDO-1 as a new type of disease-resistant activator.