桑叶、桑枝、桑白皮、桑葚等药材源于桑科植物桑Morus alba L,具有良好的生理活性。桑源药材中含有黄酮类、生物碱类、多糖类、酚酸类、Diels-Alder型和香豆素类等多种化学成分,其中黄酮类化合物、多糖或生物碱是其特征性活性成分。桑...桑叶、桑枝、桑白皮、桑葚等药材源于桑科植物桑Morus alba L,具有良好的生理活性。桑源药材中含有黄酮类、生物碱类、多糖类、酚酸类、Diels-Alder型和香豆素类等多种化学成分,其中黄酮类化合物、多糖或生物碱是其特征性活性成分。桑叶、桑枝、桑白皮、桑葚及其有效成分可能通过抑制α-葡萄糖苷酶的活性、保护胰岛β细胞、改善炎症反应、抗氧化应激、调节线粒体代谢、调节肠道菌群、改善糖尿病并发症等途径达到防治2型糖尿病的作用。本文对桑源药材的化学成分及其在2型糖尿病防治中的应用及作用机制进行了系统综述,以期为桑源药材的开发及临床合理应用提供指导。展开更多
The bushy root-2(brt-2)tomato mutant has twisting roots,and slower plant development.Here we used whole genome resequencing and genetic mapping to show that brt-2 is caused by a serine to cysteine(S75C)substitution in...The bushy root-2(brt-2)tomato mutant has twisting roots,and slower plant development.Here we used whole genome resequencing and genetic mapping to show that brt-2 is caused by a serine to cysteine(S75C)substitution in the DNA binding domain(DBD)of a heat shock factor class B(HsfB)encoded by SolycHsfB4a.This gene is orthologous to the Arabidopsis SCHIZORIZA gene,also known as AtHsfB4.The brt-2 phenotype is very similar to Arabidopsis lines in which the function of AtHsfB4 is altered:a proliferation of lateral root cap and root meristematic tissues,and a tendency for lateral root cap cells to easily separate.The brt-2 S75C mutation is unusual because all other reported amino acid substitutions in the highly conserved DBD of eukaryotic heat shock factors are dominant negative mutations,but brt-2 is recessive.We further show through reciprocal grafting that brt-2 exerts its effects predominantly through the root genotype even through BRT-2 is expressed at similar levels in both root and shoot meristems.Since AtHsfB4 is induced by root knot nematodes(RKN),and loss-of-function mutants of this gene are resistant to RKNs,BRT-2 could be a target gene for RKN resistance,an important trait in tomato rootstock breeding.Gene&accession numbers SolycHsfB4a-Solyc04g078770.展开更多
This paper investigated the effects of root-zone (RZ) CO<sub>2</sub> concentration ([CO<sub>2</sub>]) on root morphology and growth, nitrate (NO<sub>3</sub>-</sup>) uptake and...This paper investigated the effects of root-zone (RZ) CO<sub>2</sub> concentration ([CO<sub>2</sub>]) on root morphology and growth, nitrate (NO<sub>3</sub>-</sup>) uptake and assimilation of lettuce plants at different root-zone temperatures (RZT). Elevated RZ [CO<sub>2</sub>] stimulated root development, root and shoot growth compared to ambient RZ [CO<sub>2</sub>]. The greatest increase in root growth was observed in plants grown under elevated RZ [CO<sub>2</sub>] of 50,000 ppm. However, RZ [CO<sub>2</sub>] of 10,000 ppm was sufficient to achieve the maximal leaf area and shoot productivity. Lettuce plants exhibited faster shoot and root growth at 20°C-RZT than at ambient (A)-RZT. However, under elevated RZ [CO<sub>2</sub>], the magnitude of increased growth was greater at A-RZT than at 20°C-RZT. Compared to RZ [CO<sub>2</sub>] of 360 ppm, elevated RZ [CO<sub>2</sub>] of 10,000 ppm increased NO<sub>3</sub>-</sup> accumulation and nitrate reductase activity (NRA) in both leaves and roots. NO<sub>3</sub>-</sup> concentrations of leaf and root were higher at 20°C-RZT than at A-RZT in all plants. NRA was higher in root than in leaf especially under A-RZT. The total reduced nitrogen (TRN) concentration was significantly higher in plants grown under elevated RZ [CO<sub>2</sub>] of 10,000 ppm than under ambient RZ [CO<sub>2</sub>] of 360 ppm with greater concentration in 20°C-RZT plants than in A-RZT plants. These results imply that elevated RZ [CO<sub>2</sub>] significantly affected root morphology, root and shoot growth and N metabolism of temperate lettuce with greater impacts at A-RZT than at 20°C-RZT. These findings have practical significance to vegetable production by growing the vegetable crops at cool-RZT with elevated RZ [CO<sub>2</sub>] to enhance its productivity.展开更多
文摘桑叶、桑枝、桑白皮、桑葚等药材源于桑科植物桑Morus alba L,具有良好的生理活性。桑源药材中含有黄酮类、生物碱类、多糖类、酚酸类、Diels-Alder型和香豆素类等多种化学成分,其中黄酮类化合物、多糖或生物碱是其特征性活性成分。桑叶、桑枝、桑白皮、桑葚及其有效成分可能通过抑制α-葡萄糖苷酶的活性、保护胰岛β细胞、改善炎症反应、抗氧化应激、调节线粒体代谢、调节肠道菌群、改善糖尿病并发症等途径达到防治2型糖尿病的作用。本文对桑源药材的化学成分及其在2型糖尿病防治中的应用及作用机制进行了系统综述,以期为桑源药材的开发及临床合理应用提供指导。
基金The research was supported by BBSRC-UKRI fundingthe RootLINK(BB/L01954X/1)project focused on the“Understanding the Genetic Basis of Traits for Rootstock Improvement in Vegetable Crops”.
文摘The bushy root-2(brt-2)tomato mutant has twisting roots,and slower plant development.Here we used whole genome resequencing and genetic mapping to show that brt-2 is caused by a serine to cysteine(S75C)substitution in the DNA binding domain(DBD)of a heat shock factor class B(HsfB)encoded by SolycHsfB4a.This gene is orthologous to the Arabidopsis SCHIZORIZA gene,also known as AtHsfB4.The brt-2 phenotype is very similar to Arabidopsis lines in which the function of AtHsfB4 is altered:a proliferation of lateral root cap and root meristematic tissues,and a tendency for lateral root cap cells to easily separate.The brt-2 S75C mutation is unusual because all other reported amino acid substitutions in the highly conserved DBD of eukaryotic heat shock factors are dominant negative mutations,but brt-2 is recessive.We further show through reciprocal grafting that brt-2 exerts its effects predominantly through the root genotype even through BRT-2 is expressed at similar levels in both root and shoot meristems.Since AtHsfB4 is induced by root knot nematodes(RKN),and loss-of-function mutants of this gene are resistant to RKNs,BRT-2 could be a target gene for RKN resistance,an important trait in tomato rootstock breeding.Gene&accession numbers SolycHsfB4a-Solyc04g078770.
文摘This paper investigated the effects of root-zone (RZ) CO<sub>2</sub> concentration ([CO<sub>2</sub>]) on root morphology and growth, nitrate (NO<sub>3</sub>-</sup>) uptake and assimilation of lettuce plants at different root-zone temperatures (RZT). Elevated RZ [CO<sub>2</sub>] stimulated root development, root and shoot growth compared to ambient RZ [CO<sub>2</sub>]. The greatest increase in root growth was observed in plants grown under elevated RZ [CO<sub>2</sub>] of 50,000 ppm. However, RZ [CO<sub>2</sub>] of 10,000 ppm was sufficient to achieve the maximal leaf area and shoot productivity. Lettuce plants exhibited faster shoot and root growth at 20°C-RZT than at ambient (A)-RZT. However, under elevated RZ [CO<sub>2</sub>], the magnitude of increased growth was greater at A-RZT than at 20°C-RZT. Compared to RZ [CO<sub>2</sub>] of 360 ppm, elevated RZ [CO<sub>2</sub>] of 10,000 ppm increased NO<sub>3</sub>-</sup> accumulation and nitrate reductase activity (NRA) in both leaves and roots. NO<sub>3</sub>-</sup> concentrations of leaf and root were higher at 20°C-RZT than at A-RZT in all plants. NRA was higher in root than in leaf especially under A-RZT. The total reduced nitrogen (TRN) concentration was significantly higher in plants grown under elevated RZ [CO<sub>2</sub>] of 10,000 ppm than under ambient RZ [CO<sub>2</sub>] of 360 ppm with greater concentration in 20°C-RZT plants than in A-RZT plants. These results imply that elevated RZ [CO<sub>2</sub>] significantly affected root morphology, root and shoot growth and N metabolism of temperate lettuce with greater impacts at A-RZT than at 20°C-RZT. These findings have practical significance to vegetable production by growing the vegetable crops at cool-RZT with elevated RZ [CO<sub>2</sub>] to enhance its productivity.
