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Abstract [Objective] The SQUAMOSA promoter binding protein (SBP) plays an important role in plant development and abiotic stress. The aim of the study is to provide basis for understanding the function and regulation of abiotic stress response of the SBP gene family of Rhododendron henanense subsp. lingbaoense and lay foundation for species protection. [Methods] SBP gene family members in the genome of R. henanense subsp. lingbaoense was identified and analyzed by bioinformatics method. Tissue specificity was analyzed based on transcriptome data and qRT-PCR was used to detect the response of SBP gene expression to abiotic stress. [Results] (1) 19 SBP genes containing SBP conserved domains were identified in the reference genome of Lingbao rhododendron, the length of amino acids encoded by the genes ranged from 179-1 072 aa with molecular weight ranging from 20.26-118.73 kD. The proteins were located in the nucleus, and the genes were unevenly distributed on 8 chromosomes. (2) 19 RhlSBPs were divided into 5 subfamilies by phylogenetic analysis and most RhlSBPs were clustered with Arabidopsis AtSPL family members. (3) All RhlSBPs shared motif 1, motif 2, and motif 4, and the number of introns in subfamilies Ⅳ and Ⅴ was much higher than that in subfamilies Ⅰ, Ⅱ, and Ⅲ. (4) RhlSBP promoters contained a large number of light responsive elements, hormone responsive elements, and stress responsive elements, suggesting that RhlSBPs may play an important role in response to light regulation and abiotic stress. (5) The orthology of SBP genes between Lingbao rhododendron and R. williamsianum and R. molle which were in the same family was higher. (6) The RhlSBP gene subfamily members had similar tissue expression patterns. (7) RhlSBP genes functioned in response to abiotic stress, but members responded differently to different stresses. Under methyl jasmonate (MeJA) and low temperature treatments, gene expression was up-regulated, while salt treatment inhibited RhlSBP expression. Under drought conditions, RhlSBP expression was up-regulated and then down-regulated. [Conclusion] RhlSBP1 and RhlSBP8 may be the key genes induced by drought, low temperature, and MeJA.

Taxadiene is the first committed precursor to paclitaxel, marketed as Taxol, arguably the most important anticancer agent against ovarian and breast cancer. In Taxus, taxadiene is directly synthesized from geranylgeranyl diphosphate (GGPP) that is the common precursor for diterpenoids and is found in most plants and microbes. In this study, Artemisia annua L., a Chinese medicinal herb that grows fast and is rich in terpenoids, was used as a genetic engineering host to produce taxadiene. The TXS (taxadiene synthase) gene, cloned from Taxus and inserted into pCAMBIA1304, was transformed into Artemisia annua L. using the Agrobacterium tumefaciens-mediated method. Thirty independent transgenic plants were obtained, and GC-MS analysis was used to confirm that taxadiene was produced and accumulated up to 129.7 μg/g dry mass. However, the high expression of TXS did not affect plant growth or photosynthesis in transgenic Artemisia annua L. It is notable that artemisinin is produced and stored in leaves and most taxadiene accumulated in the stem of transgenic Artemisia annua L., suggesting a new way to produce two important compounds in one transgenic plant: leaves for artemisinin and stem for taxadiene. Overall, this study demonstrates that genetic engineering of the taxane biosynthetic pathway in Artemisia annua L. for the production of taxadiene is feasible. [ABSTRACT FROM AUTHOR]

The endophytic fungus named FSN006 was isolated from the inner bark of Juglans mandshurica. It grew quickly and formed circular colony on PDA plate. The upper side of the colony was white, while the lower side of the colony and the conditioned medium were light yellow as a result of significant yellow pigment substances were produced and secreted by the fungi. Green elliptic conidia appeared when cultured on CMX plate. Based on the morphology identification and ITS sequence, it was clear that this fungus belonged to the Deuteromycotina, HyPhomycetes, Moniliales, Trichoderma longibrachiatum. The conditioned medium of FSN006 showed a high anti-tumor ability against liver cancer cell-HepG2, and reached its IC50 concentration after being diluted 20 times, while the IC50 concentration of curcumine was(11.49 +/- 0.12) mg x L(-1). In addition, there was preeminent selective inhibiting effect against the normal liver cell strain HL-7702 and its caner counter strain HepG2. The inhibiting effect against strain HL-7702 was only one quarter of that against HepG2 at the concentration of IC50. Therefore, the fermentation of FSN006 may provide a possible way to produce anticancer drug with higher efficiency and lower toxicity.