Effect of salt-alkali stress on seed germination of the halophyte Halostachys caspica.

The increasing global phenomenon of soil salinization has prompted heightened interest in the physiological ecology of plant salt and alkali tolerance. Halostachys caspica belonging to Amaranthaceae, an exceptionally salt-tolerant halophyte, is widely distributed in the arid and saline-alkali regions of Xinjiang, in Northwest China. Soil salinization and alkalinization frequently co-occur in nature, but very few studies focus on the interactive effects of various salt and alkali stress on plants. In this study, the impacts on the H. caspica seed germination, germination recovery and seedling growth were investigated under the salt and alkali stress. The results showed that the seed germination percentage was not significantly reduced at low salinity at pH 5.30-9.60, but decreased with elevated salt concentration and pH. Immediately after, salt was removed, ungerminated seeds under high salt concentration treatment exhibited a higher recovery germination percentage, indicating seed germination of H. caspica was inhibited under the condition of high salt-alkali stress. Stepwise regression analysis indicated that, at the same salt concentrations, alkaline salts exerted a more severe inhibition on seed germination, compared to neutral salts. The detrimental effects of salinity or high pH alone were less serious than their combination. Salt concentration, pH value, and their interactions had inhibitory effects on seed germination, with salinity being the decisive factor, while pH played a secondary role in salt-alkali mixed stress.

Tissue culture and Agrobacterium-mediated genetic transformation of the oil crop sunflower.

Sunflower is one of the four major oil crops in the world. 'Zaoaidatou' (ZADT), the main variety of oil sunflower in the northwest of China, has a short growth cycle, high yield, and high resistance to abiotic stress. However, the ability to tolerate adervesity is limited. Therefore, in this study, we used the retention line of backbone parent ZADT as material to establish its tissue culture and genetic transformation system for new variety cultivating to enhance resistance and yields by molecular breeding. The combination of 0.05 mg/L IAA and 2 mg/L KT in MS was more suitable for direct induction of adventitious buds with cotyledon nodes and the addition of 0.9 mg/L IBA to MS was for adventitious rooting. On this basis, an efficient Agrobacterium tumefaciens-mediated genetic transformation system for ZADT was developed by the screening of kanamycin and optimization of transformation conditions. The rate of positive seedlings reached 8.0%, as determined by polymerase chain reaction (PCR), under the condition of 45 mg/L kanamycin, bacterial density of OD600 0.8, infection time of 30 min, and co-cultivation of three days. These efficient regeneration and genetic transformation platforms are very useful for accelerating the molecular breeding process on sunflower.

Genome-Wide Identification and Expression Analysis of TGA Family Genes Associated with Abiotic Stress in Sunflowers (Helianthus annuus L.).

Sunflower (Helianthus annuus L.) is an important, substantial global oil crop with robust resilience to drought and salt stresses. The TGA (TGACG motif-binding factor) transcription factors, belonging to the basic region leucine zipper (bZIP) family, have been implicated in orchestrating multiple biological processes. Despite their functional significance, a comprehensive investigation of the TGA family's abiotic stress tolerance in sunflowers remains elusive. In the present study, we identified 14 TGA proteins in the sunflower genome, which were unequally distributed across 17 chromosomes. Employing phylogenetic analysis encompassing 149 TGA members among 13 distinct species, we revealed the evolutionary conservation of TGA proteins across the plant kingdom. Collinearity analysis suggested that both HaTGA01 and HaTGA03 were generated due to HaTGA08 gene duplication. Notably, qRT-PCR analysis demonstrated that HaTGA04, HaTGA05, and HaTGA14 genes were remarkably upregulated under ABA, MeJA, and salt treatments, whereas HaTGA03, HaTGA06, and HaTGA07 were significantly repressed. This study contributes valuable perspectives on the potential roles of the HaTGA gene family under various stress conditions in sunflowers, thereby enhancing our understanding of TGA gene family dynamics and function within this agriculturally significant species.

lncRNA ZNF674-AS1 regulates the proliferation and migration of cervical cancer HCC94 cells via miR-510-5p/REPS2 axis / 中国肿瘤生物治疗杂志

@#[摘 要] 目的：探讨lncRNA ZNF674-AS1在宫颈癌中的作用及其分子机制。方法：用qPCR法检测ZNF674-AS1在31例2019年1月至2020年7月在武汉儿童医院接受手术治疗患者的宫颈癌组织和对应的癌旁组织、宫颈癌细胞系（SiHa、HeLa、C33A和HCC94）和永生化子宫颈上皮细胞系中的表达。转染过表达ZNF674-AS1质粒及其阴性对照质粒至ZNF674-AS1表达最少的HCC94细胞，CCK-8法和Transwell实验检测过表达ZNF674-AS1对HCC94细胞增殖活性和迁移能力的影响。生物信息学方法预测和双荧光素酶报告基因实验验证ZNF674-AS1和miR-510-5p、REPS2三者间的互补结合关系。qPCR检测过表达ZNF674-AS1对miR-510-5p与REPS2表达的影响，WB法检测过表达ZNF674-AS对细胞增殖和迁移相关因子表达的影响。结果：与癌旁组织相比，ZNF674-AS1在宫颈癌组织中呈明显低表达（P<0.01）；与永生化子宫上皮细胞相比，ZNF674-AS1在宫颈癌细胞系中也呈明显低表达（P<0.05或P<0.01），以HCC94细胞中表达最低（P<0.01）。过表达ZNF674-AS1能明显抑制HCC94细胞的增殖（P<0.05）和迁移（P<0.01）。与ZNF674-AS1相互作用的miRNA是miR-510-5p，与miR-510-5p相互作用的基因是REPS2。过表达ZNF674-AS1导致HCC94细胞中miR-510-5p的表达水平降低（P<0.01）而REPS2基因的表达水平升高（P<0.01），同时引起细胞增殖和迁移相关的多种因子（CDK2、cyclin D3、vimentin和twist）上调或下调。结论：lncRNA ZNF674-AS1在宫颈癌组织和细胞中呈低表达，可能通过竞争性结合miR-510-5p而上调REPS2的表达，从而抑制宫颈癌HCC94细胞的增殖和迁移。