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The two tree peony species, namely, Paeonia ludlowii (Stern & G. Taylor) D. Y. Hong and P. delavayi Franch, belongs to the section Moutan Paeonia (Paeoniaceae). They are the only sources of yellow pigment in tree peony cultivar breeding. P. ludlowii has been listed as “critically endangered”, whereas P. delavayi has been listed as “near threatened” species according to the China Species Red List. The complete chloroplast genome sizes of P. ludlowii and P. delavayi are 152,687 and 154,405 bp respectively. Both contain a 17,056 bp long small single copy region (SSC). The large single copy region (LSC) in P. ludlowii is 84,613 bp, whereas the inverted repeat regions (IRs) are 25,644 bp. In addition, LSC in P. delavayi is 86,142 bp, whereas the IRs is 25,650 bp. The genomes of the two species encode the same set of 134 genes, including 86 protein-coding genes, 8 ribosomal RNA genes and 40 transfer RNA genes. Phylogenetic analysis revealed that all five Paeonia species clustered together, and P. ludlowii and P. delavayi are most closely related to each other. These newly characterized chloroplast genomes will provide essential data for the further conservation of P. ludlowii and P. delavayi.

Sophora moorcroftiana, an endemic Fabaceae species occurred in the Qinghai-Tibet plateau, China, has important economic value in local. Its completed plastome sequence is 148,930 bp in size, and co...

Dracocephalum tanguticum Maxim, a Lamiaceae species endemic to the Qinghai-Tibetan Plateau and adjacent regions, is an important ornamental, medicinal and aromatic herb. In this study, a comprehensive transcriptome of 18 libraries from six organs namely, roots, stems, leaves, sepals, flowers and seeds of D. tanguticum were generated. More than 100 Gb of sequence data were obtained and assembled de novo into 187,447 transcripts, including 151,463 unigenes, among which the six organs shared 17.7% (26,841). In addition, all unigenes were assigned to 362 pathways, in which ‘biosynthesis of secondary metabolites’ is the second enriched pathway. Furthermore, rosmarinic acid (RA) is one of the multifunctional phenolic bioactive compounds produced in some Lamiaceae species. The six organs of D. tanguticum were confirmed to produce RA. A total of 22 predicted biosynthetic genes related to RA from the transcriptome were further isolated. Two of these genes were identified as candidates by evaluating the correlation coefficient between the RA contents and the expression of the predicted biosynthetic genes in the six organs. The new sequence information will improve the knowledge of D. tanguticum, as well as provide a reference tool for future studies of biosynthetic genes related to RA in this species.

Tibetan hulless barley (Hordeumvulgare subsp. vulgare) is exposed to harsh environmental factors, such as drought, salinity, and cold. To explore useful transcription factor genes that could improve stress resistance of Tibetan hulless barley varieties, five WRKY genes were isolated from drought tolerance Tibetan hulless barley genotype TR1, namely, HvvWRKY2, HvvWRKY5, HvvWRKY10, HvvWRKY19, and HvvWRKY46. The HvvWRKY46 belongs to Group I of the WRKY superfamily, whereas the remaining four belong to Group II. All of them were localized to the nucleus of onion epidermal cells. The respective expression of the five WRKY genes was compared under drought, salt, and cold stress in resistant genotype TR1 and sensitive genotype TS1. Among the five, HvvWRKY2, HvvWRKY5, HvvWRKY19, and HvvWRKY46 were induced by drought or PEG6000 stress in TR1 but not in TS1, suggesting that these four WRKY genes are involved in drought resistance. HvvWRKY2 was induced by salt stress in TR1 but not in TS1, indicating that HvvWRKY2 may be involved in salt resistance. What’s more, HvvWRKY2 were notably up-regulated in TR1 under cold stress, whereas it was only induced at low level in TS1, indicating that HvvWRKY2 may also participate in cold tolerance.

Various plant species in the Qinghai-Tibet Plateau exposed to harsh conditions, such as low oxygen, drought, extremely low temperatures and salinity, have evolved both molecular and physiological adaptation strategies to deal with these multiple stresses. Sophora moorcroftiana (Benth.) Baker (Fabaceae) is a highly drought-resistant endemic Sophora shrub species in the Qinghai-Tibet Plateau. In our previous study, a drought-induced DREB transcription factor gene was identified and was designated as SmDREB1. SmDREB1-GFP fusion construct was introduced into Arabidopsis protoplast to characterise the function of SmDREB1 in drought resistance. The results showed that SmDREB1 targets the nucleus of Arabidopsis protoplast. Ectopic expression of SmDREB1 in model plant species Arabidopsis was performed. The transgenic lines showed increasing expressions of drought marker genes including AtDHN, AtLEA, AtPIP2 ;2, AtPIP2;3 and AtRD29, increasing activities of antioxidant enzymes and proline contents and increasing light-use efficiency under drought stress as compared with the wild-type plants; SmDREB1 transgenic lines are more resistant to drought than wild-type plants. Therefore, the SmDREB1 is a drought-resistant transcription factor gene of S. moorcroftiana and could be a candidate in genetic engineering to improve drought resistance of plateau plant species.

RING finger proteins comprise a large family and play important roles in regulation of growth and development, hormone signalling, and responses to biotic and abiotic stresses in plants. In this study, the identification and functional characterization of a C4C4-type RING finger protein gene from the Chinese wild grapevine Vitis pseudoreticulata (designated VpRFP1) are reported. VpRFP1 was initially identified as an expressed sequence tag (EST) from a cDNA library constructed from leaves of V. pseudoreticulata inoculated with the grapevine powdery mildew Uncinula necator. Sequence analysis of the deduced VpRFP1 protein based on the full-length cDNA revealed an N-terminal nuclear localization signal (NLS) and a C-terminal C4C4-type RING finger motif with the consensus sequence Cys-X(2)-Cys-X(13)-Cys-X(1)-Cys-X(4)-Cys-X(2)-Cys-X(10)-Cys-X(2)-Cys. Upon inoculation with U. necator, expression of VpRFP1 was rapidly induced to higher levels in mildew-resistant V. pseudoreticulata plants. In contrast, expression of VpRFP1 was down-regulated in mildew-susceptible V. vinifera plants. Western blotting using an antibody raised against VpRFP1 showed that VpRFP1 was also induced to higher levels in V. pseudoreticulata plants at 12-48 hours post-inoculation (hpi). However, there was only slight increase in VpRFP in V. vinifera plants in the same time frame, even though a more significant increase was observed at 96-144 hpi in these plants. Results from transactivation assays in yeast showed that the RING finger motif of VpRFP1 exhibited some activity of transcriptional activation; however, no activity was seen with the full-length VpRFP1. Overexpression of VpRFP1 in Arabidopsis plants was found to enhance resistance to Arabidopsis powdery mildew Golovinomyces cichoracearum, which seemed to be correlated with increased transcript levels of AtPR1 and AtPR2 in the pathogen-infected tissues. In addition, the Arabidopsis transgenic lines showed enhanced resistance to a virulent bacterial pathogen Pseudomonas syringae pv. tomato DC3000. Taken together, the results suggested that VpRFP1 may be a transcriptional activator of defence-related genes in grapevines.

In this study, two WRKY genes were isolated from Erysiphe necator-resistant Chinese wild Vitis pseudoreticulata W. T. Wang 'Baihe-35-1', and designated as VpWRKY1 (GenBank accession no. GQ884198) and VpWRKY2 (GenBank accession no. GU565706). Nuclear localization of the two proteins was demonstrated in onion epidermal cells, while trans-activation function was confirmed in the leaves of 'Baihe-35-1'. Expression of VpWRKY1 and VpWRKY2 was induced rapidly by salicylic acid treatment in 'Baihe-35-1'. Expression of VpWRKY1 and VpWRKY2 was also induced rapidly by E. necator infection in 11 grapevine genotypes; the maximum induction of VpWRKY1 was greater in E. necator-resistant grapevine genotypes than in susceptible ones post E. necator inoculation. Furthermore, ectopic expression of VpWRKY1 or VpWRKY2 in Arabidopsis enhanced resistance to powdery mildew Erysiphe cichoracearum, and enhanced salt tolerance of transgenic plants. VpWRKY2 also enhanced cold tolerance of transgenic plants. In addition, the two proteins were shown to regulate the expression of some defense marker genes in Arabidopsis and grapevine. The data suggest that VpWRKY1 and VpWRKY2 may underlie the resistance in transgenic grapevine to E. necator and tolerance to salt and cold stresses.

Choice of native woody species with higher drought tolerance is the basic work on afforestation in Qinghai–Tibet Plateau (QTP) region. However, no systemic evaluation has been made of the drought tolerance ability. In the present study, we compared the drought injury degree and ten physiological and biochemical indices from six native deciduous and broad-leaved woody plant species seedlings under continuous drought for 21 days. The ten indices included relative water content, net photosynthetic rate, transpiration, water use efficiency, superoxide dismutase, peroxidase, catalase and malondialdehyde, proline and soluble sugars contents of leaves. Under drought stress, six native species showed the different response. According to analysis of the mean membership function values, the drought tolerance of six native species could be ranked in the following order: Berberis hemsleyana > Sophora viciifolia > Betula platyphylla > Cotoneaster rotundifolius > Prunus mira > Hippophae rhamnoides. Species B. hemsleyana and S. viciifolia were relatively high drought-tolerant, while P. mira and H. rhamnoides were relatively low tolerant. The two high-tolerant native species resist to drought by different strategies after long-term adaptation, and these two species should be given prior consideration in deciduous woody plant species selection for afforestation in arid and semi-arid area of QTP in the future.

Ethylene response factor (ERF) functions as an important plant-specific transcription factor in regulating biotic and abiotic stress response through interaction with various stress pathways. We previously obtained three ERF members, VpERF1, VpERF2, and VpERF3 from a highly powdery mildew (PM)-resistant Chinese wild Vitis pseudoreticulata cDNA full-length library. To explore their functions associated with plant disease resistance or biotic stress, we report here to characterize three ERF members from this library. PM-inoculation analysis on three different resistant grapevine genotypes revealed that three VpERFs displayed significant responses, but a different expression pattern. Over-expression of VpERF1, VpERF2, and VpERF3 in transgenic tobacco plants demonstrated that VpERF2 and VpERF3 enhanced resistance to both bacterial pathogen Ralstonia solanacearum and fungal pathogen Phytophtora parasitica var. nicotianae Tucker. Importantly, VpERF1-overexpressing transgenic Arabidopsis plants increased susceptibility toward these pathogens. Investigation on drought, cold, and heat treatments suggested, VpERF2 was distinctly induced, whereas VpERF3 displayed a very weak response and VpERF1 was distinctly induced by drought and heat. Concurrently, VpERF3 was significantly induced by salicylic acid (SA), methyl jasmonate (MeJA), and ET. Our results showed that the three VpERFs from Chinese wild V. pseudoreticulata play different roles in either preventing disease progression via regulating the expression of relevant defense genes, or directly involving abiotic stress responsive pathways.