Zinc(Zn) is an essential mineral element for plant growth and development. Zn deficiency in crops frequently occurs in many types of soils. It is therefore crucial to identify genetic resources linking Zn acquisition ...Zinc(Zn) is an essential mineral element for plant growth and development. Zn deficiency in crops frequently occurs in many types of soils. It is therefore crucial to identify genetic resources linking Zn acquisition traits and development of crops with improved Zn-use efficiency for sustainable crop production. In this study, we functionally identified a rice uncharacterized ABCG(ATP-binding cassette G-subfamily) gene encoding a PDR20(pleiotropic drug resistance 20) metal transporter for mediation of rice growth, seed development and Zn accumulation. OsPDR20 was localized to the plasma membrane, but it was not transcriptionally induced under Zn deficiency, rather was sufficiently up-regulated under high level of Zn stress. Yeast(Saccharomyces cerevisiae) transformed with OsPDR20 displayed a relatively lower Zn accumulation with attenuated cellular growth, suggesting that OsPDR20 had an activity for Zn transport. Knocking-down OsPDR20 by RNA interference(RNAi) compromised rice growth with shorter plant height and decreased biomass in rice plantlets grown under hydroponic media. Zn concentration in the roots of OsPDR20 knocked-down rice lines declined under Zn deficiency, while they remained unchanged compared with the wild type under normal Zn supply. A rice lifelong field trial demonstrated that OsPDR20 mutation impaired the capacity of seed development, with shortened panicle and seed length, compromised spikelet fertility, and reduced grain number per plant or grain weight per unit area. Interestingly, OsPDR20 mutation elevated the accumulation of Zn in husk and brown rice over the wild type. Overall, this study pointed out that OsPDR20 is fundamentally required for rice growth and seed development through Zn transport and homeostasis.展开更多
目的观察鸦胆子乳剂对非小细胞肺癌患者血清MMP-2水平的调控作用。方法随机将40例非小细胞肺癌患者分成对照组及治疗组各20例。治疗组:鸦胆子乳剂注射液30 mL qd×30 d+TP方案静脉化疗2疗程。对照组:单用TP方案(用法剂量同治疗组)...目的观察鸦胆子乳剂对非小细胞肺癌患者血清MMP-2水平的调控作用。方法随机将40例非小细胞肺癌患者分成对照组及治疗组各20例。治疗组:鸦胆子乳剂注射液30 mL qd×30 d+TP方案静脉化疗2疗程。对照组:单用TP方案(用法剂量同治疗组)静脉化疗2个疗程。分别于化疗前一天、第二个疗程结束后(即第42天)按酶联免疫吸附测定(enzyme-linked immunosorbent assay简称ELISA)技术要求收集标本送检。结果血清MMP-2水平与TNM分期呈线性关系;治疗组其下调MMP-2水平高于对照组,两组差异有统计学意义,P<0.05;两组有效率、获益率治疗组虽有升高,差别无显著意义,P>0.05。结论非小细胞肺癌患者血清MMP-2水平与肺癌进展和预后相关;鸦胆子乳剂具下调非小细胞肺癌患者血清MMP-2水平的作用,即有一定的MMP抑制物样作用。展开更多
基金financially supported by the National Natural Science Foundation of China(Grant No.21777072)。
文摘Zinc(Zn) is an essential mineral element for plant growth and development. Zn deficiency in crops frequently occurs in many types of soils. It is therefore crucial to identify genetic resources linking Zn acquisition traits and development of crops with improved Zn-use efficiency for sustainable crop production. In this study, we functionally identified a rice uncharacterized ABCG(ATP-binding cassette G-subfamily) gene encoding a PDR20(pleiotropic drug resistance 20) metal transporter for mediation of rice growth, seed development and Zn accumulation. OsPDR20 was localized to the plasma membrane, but it was not transcriptionally induced under Zn deficiency, rather was sufficiently up-regulated under high level of Zn stress. Yeast(Saccharomyces cerevisiae) transformed with OsPDR20 displayed a relatively lower Zn accumulation with attenuated cellular growth, suggesting that OsPDR20 had an activity for Zn transport. Knocking-down OsPDR20 by RNA interference(RNAi) compromised rice growth with shorter plant height and decreased biomass in rice plantlets grown under hydroponic media. Zn concentration in the roots of OsPDR20 knocked-down rice lines declined under Zn deficiency, while they remained unchanged compared with the wild type under normal Zn supply. A rice lifelong field trial demonstrated that OsPDR20 mutation impaired the capacity of seed development, with shortened panicle and seed length, compromised spikelet fertility, and reduced grain number per plant or grain weight per unit area. Interestingly, OsPDR20 mutation elevated the accumulation of Zn in husk and brown rice over the wild type. Overall, this study pointed out that OsPDR20 is fundamentally required for rice growth and seed development through Zn transport and homeostasis.
