WD40 is a kind of scaffold protein, which is widely involved in various processes such as plant growth and development, anthocyanin biosynthesis, and biotic/abiotic stresses. Using bioinformatics technology, we identified 258 HbWD40 family members from the rubber tree（Hevea brasiliensis） genome,and systematically analyzed their chromosomal distribution, protein conserved domains, tissue-specific expression, and expression patterns under low temperature stress. The results showed that HbWD40members were distributed on all 18 chromosomes; the HbWD40 family could be divided into 28 subfamilies according to different conserved domains. The results of expression pattern showed that 175 members were expressed in all 5 tissues, and 8 differentially expressed members were identified under low temperature stress. We further cloned HbWD40-168 gene by RT-PCR technique. The coding sequence（CDS） of this gene was 1 335 bp in length, encoding a putative protein of 444 amino acids. Conserved domain analysis showed that HbWD40-168 contained four WD40 repeat elements and two ZnF＿C3H1 zinc finger protein domains. Promoter analysis revealed the presence of multiple hormone-or stress-related cis-acting elements in the promoter region of HbWD40-168. Subcellular localization showed that HbWD40-168 localized in the nucleus. This study provides a basis for in-depth identification of the biological functions of the HbWD40 family in rubber trees.
Protoplasts are widely used in genetic transformation, physiological and biochemical fields, for it is easy to absorb exogenous substances. Also, an efficient protoplast isolation system and transient transformation system are the basis for molecular biology and related research. In recent years, plant protoplast isolation and transformation technology has achieved rapid development and application. Currently,the commonly used methods for plant protoplasts transient transformation include Agrobacterium infiltration, polyethylene glycol（PEG） mediation, electroporation, plant virus vectors and biolistic methods. This paper summarizes protoplast isolation steps, the factors affecting protoplasts isolation and purification,plant transient transformation methods and transient expression systems application fields, in order to provide reference for the establishment of more plant protoplast isolation systems and transient transformation systems.
In this paper, based on transcriptome library of Oncidium after soft rot infection, 72 WRKY protein sequences were identified, with a length distribution of 110–719 amino acids, an average length of 319.8 amino acids. Among the 72 WRKY protein sequences, 14 sequences were classified into group Ⅰ, 42sequences were classified into group Ⅱ, and 16 sequences were classified into group Ⅲ. Group Ⅱ could be further divided into 7 subgroups. Those 72 protein sequences contain at least one WRKY domain and C2H2 type zinc finger motif, of which the sequences from group I contain two WRKY domains. 12 WRKY genes were screened for fluorescence quantitative PCR analysis, results showed that the expression pattern of those 12 WRKY genes basically verified the high-throughput expression pattern, and the responses pattern could be divided into three types. Among them, OncWRKY44（Ⅰ）, OncWRKY69（Ⅱg） and OncWRKY70（Ⅱg） 3 WRKY genes from the first and third types could be induced by salicylic acid and methyl jasmonate,and showed the highest expression level in the infection site of symbiotic plants, which may be important node genes involved in the induced system resistance brought by Piriformospora indica.
The effect of Arabidopsis seed oil content on seed longevity was studied using the mutants with decreased seed oil content and overexpressing line with increased seed oil content. The results indicated that the wri1-1, wri1-4, fus3-T, AS11（dgat1-1） and ABX45（dgat1-2） mutants, which accumulates less triacylglycerol（TAG） in seeds, exhibit defect in seed longevity. On the contrary, the 35S-WRI1 overexpressing seeds with more accumulated TAG show an increase in seed longevity. Moreover, wri1-1 and wri1-4 are more sensitive to oxidative stress, compared to wild type. The treatment by ascorbic acid rescued the decrease of germination rate of these aged seeds. In summary, the storage TAG of Arabidopsis seeds may affect seed vigor through the reactive oxygen species（ROS） scavenging system.
Flowers are the reproductive organs of angiosperms, and flowering control is of great significance to the production of crops and ornamental plants. Flowers open in a variety of ways, the time required for flowers to open is also varies. The opening and closing of flowers are accompanied by a variety of physiological processes, such as cell expansion, elongation and changes in cell osmotic pressure,which are regulated by light, temperature, water, phytohormones and other factors. This paper reviews the flowering regulation mechanism from the aspects of physiological process, pollination effect and environmental factors, and provides a theoretical basis for further research on flowering regulation mechanism.
