Transcriptome profile analysis of Indian mustard (Brassica juncea L.) during seed germination reveals the drought stress-induced genes associated with energy, hormone, and phenylpropanoid pathways.

Indian mustard (Brassica juncea L. Czern and Coss) is an important oil and vegetable crop frequently affected by seasonal drought stress during seed germination, which retards plant growth and causes yield loss considerably. However, the gene networks regulating responses to drought stress in leafy Indian mustard remain elusive. Here, we elucidated the underlying gene networks and pathways of drought response in leafy Indian mustard using next-generation transcriptomic techniques. Phenotypic analysis showed that the drought-tolerant leafy Indian mustard cv. 'WeiLiang' (WL) had a higher germination rate, antioxidant capacity, and better growth performance than the drought-sensitive cv. 'ShuiDong' (SD). Transcriptome analysis identified differentially expressed genes (DEGs) in both cultivars under drought stress during four germination time points (i.e., 0, 12, 24, and 36 h); most of which were classified as drought-responsive, seed germination, and dormancy-related genes. In the Kyoto Encyclopedia of Genes and Genome (KEGG) analyses, three main pathways (i.e., starch and sucrose metabolism, phenylpropanoid biosynthesis, and plant hormone signal transduction) were unveiled involved in response to drought stress during seed germination. Furthermore, Weighted Gene Co-expression Network Analysis (WGCNA) identified several hub genes (novel.12726, novel.1856, BjuB027900, BjuA003402, BjuA021578, BjuA005565, BjuB006596, novel.12977, and BjuA033308) associated with seed germination and drought stress in leafy Indian mustard. Taken together, these findings deepen our understanding of the gene networks for drought responses during seed germination in leafy Indian mustard and provide potential target genes for the genetic improvement of drought tolerance in this crop.

Total Flavonoids in Premna Fulva Craib Alleviates Brain Neurological Impairment and Influences Nrf2 and HO-1 Expressions in Rats with Ischemia-Reperfusion.

Total flavonoids in Premna fulva Craib (TFPFC) are a kind of flavonoid compound synthesized via photosynthesis extracted from Premna fulva Craib, which possess a strong anti-oxidative effect. Cerebral Ischemia-Reperfusion refers to the body's damage mainly caused by oxidative stress. This study aims to investigate the alleviating effect of TFPFC on brain neurological impairment and its influences on Nuclear factor E2-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1) expressions in rats with Ischemia-Reperfusion. The rat model of Ischemia-Reperfusion was established, and rats were treated with TFPFC or normal saline. At 24 h after reperfusion, the neurological score, volume of cerebral infarction and cerebral water content were analyzed in different groups. The influences of TFPFC treatment on the proliferative activity and apoptosis of oxygen and glucose deprivation/reoxygenation (OGD/R) neural stem cells were detected via methyl thiazolyl tetrazolium (MTT) assay and flow cytometry. Moreover, the malondialdehyde (MDA) level and superoxide dismutase (SOD) activity were measured to evaluate the oxidative stress effect. The influences of TFPFC treatment on the protein and messenger ribonucleic acid (mRNA) expressions of Nrf2 and HO-1 were analyzed using reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting. The TFPFC treatment alleviated the neurological impairment in rats after Ischemia-Reperfusion and reduced the volume of cerebral infarction and cerebral edema status in rats with Ischemia-Reperfusion. TFPFC increased the proliferative activity of OGD/R neural stem cells and decreased damage and apoptosis. In addition, the TFPFC treatment reduced the MDA level, improved the SOD activity, and up-regulated the protein and mRNA expressions of Nrf2 and HO-1. The TFPFC treatment may improve oxidative damage and protect the nervous system through the up-regulation of expressions of transcription factors Nrf2 and HO-1.