Twelve new Schiff bases of thiadiazole have been synthesized for the first time. Their physical constants, UV, IR, 1H NMR and elementary analysis were originally characterized, biological activity were originally stud...Twelve new Schiff bases of thiadiazole have been synthesized for the first time. Their physical constants, UV, IR, 1H NMR and elementary analysis were originally characterized, biological activity were originally studied. It is found from the results of biological activity tests that some compounds have a remarkable activity on plant growth hormone. Compounds Ⅲa and Ⅲk have a good activity on cytokinin, compounds Ⅲe and Ⅲj and Ⅲl have an excellent activity on auxin.展开更多
The present study investigated whether an irrigation system could be established to save water and increase grain yield to enhance water productivity by proper water management at the field level in irrigated lowland ...The present study investigated whether an irrigation system could be established to save water and increase grain yield to enhance water productivity by proper water management at the field level in irrigated lowland rice （Oryza sativa L.）. Using two field-grown rice cultivars, two irrigation systems; conventional irrigation and water-saving irrigation, were conducted. In the water-saving irrigation system, limiting values of soil water potential related to specific growth stages were proposed as irrigation indices. Compared with conventional irrigation where drainage was in mid-season and flooded at other times, the water-saving irrigation increased grain yield by 7.4% to 11.3%, reduced irrigation water by 24.5% to 29.2%, and increased water productivity （grain yield per cubic meter of irrigation water） by 43.1% to 50.3%. The water-saving irrigation significantly increased harvest index, improved milling and appearance qualities, elevated zeatin-I-zeaUn riboside concentrations in root bleedings and enhanced activities of sucrose synthase, adenosine diphosphate glucose pyrophosphorylase, starch synthase and starch branching enzyme in grains. Our results indicate that water-saving irrigation by controlling limiting values of soil water potential related to specific growth stages can enhance physiological activities of roots and grains, reduce water input, and increase grain yield.展开更多
Plant hormones regulate many aspects of plant growth and development. Both auxin and cytokinin have been known for a long time to act either synergistically or antagonistically to control several significant developme...Plant hormones regulate many aspects of plant growth and development. Both auxin and cytokinin have been known for a long time to act either synergistically or antagonistically to control several significant developmental processes, such as the formation and maintenance of meristem. Over the past few years, exciting progress has been made to reveal the molecular mechanisms underlying the auxin-cytokinin action and interaction. In this review, we shall briefly discuss the major progress made in auxin and cytokinin biosynthesis, auxin transport, and auxin and cytokinin signaling. The frameworks for the complicated interaction of these two hormones in the control of shoot apical meristem and root apical meristem formation as well as their roles in in vitro organ regeneration are the major focus of this review.展开更多
The seed_specific phaseolin promoter (Ph/P) was fused to an ipt gene, then was cloned to a plant expression vector containing a gus gene driven by a 35S promoter. Cotton (Gossypium hirsutum L.) plants were tr...The seed_specific phaseolin promoter (Ph/P) was fused to an ipt gene, then was cloned to a plant expression vector containing a gus gene driven by a 35S promoter. Cotton (Gossypium hirsutum L.) plants were transformed through pollen tube pathway methods. After seed germination, histochemical staining of the roots demonstrated that 32 GUS positive plants were obtained and three of which contained the chimeric Ph/P_ ipt transgene as confirmed by PCR analysis. An immunosorbent assay showed that two of the three transgenic cotton lines contained higher levels of zeatin equivalents in seeds than the control. Seedling development of these two transgenic lines differed from the control in a reduction of the shoot growth, showing a stunted phenotype as expected, but a surprisingly developed root system with a 3-4 fold fast_growing lateral roots. In addition, fibers (seed_hairs) of the two transgenic cotton lines were considerably shorter than those of the control. These results indicate that genetic engineering may be used to manipulate the development of cotton plants, particularly cotton fibers.展开更多
文摘Twelve new Schiff bases of thiadiazole have been synthesized for the first time. Their physical constants, UV, IR, 1H NMR and elementary analysis were originally characterized, biological activity were originally studied. It is found from the results of biological activity tests that some compounds have a remarkable activity on plant growth hormone. Compounds Ⅲa and Ⅲk have a good activity on cytokinin, compounds Ⅲe and Ⅲj and Ⅲl have an excellent activity on auxin.
基金Supported by the National Natural Science Foundation of China(30671225)the State Key Project(2004-BA520A12-5)+1 种基金the Natural Science Foundation of Jiangsu Province(BK2006069)Hong Kong Research Grants Council(Project HKBU 2465/05M).
文摘The present study investigated whether an irrigation system could be established to save water and increase grain yield to enhance water productivity by proper water management at the field level in irrigated lowland rice （Oryza sativa L.）. Using two field-grown rice cultivars, two irrigation systems; conventional irrigation and water-saving irrigation, were conducted. In the water-saving irrigation system, limiting values of soil water potential related to specific growth stages were proposed as irrigation indices. Compared with conventional irrigation where drainage was in mid-season and flooded at other times, the water-saving irrigation increased grain yield by 7.4% to 11.3%, reduced irrigation water by 24.5% to 29.2%, and increased water productivity （grain yield per cubic meter of irrigation water） by 43.1% to 50.3%. The water-saving irrigation significantly increased harvest index, improved milling and appearance qualities, elevated zeatin-I-zeaUn riboside concentrations in root bleedings and enhanced activities of sucrose synthase, adenosine diphosphate glucose pyrophosphorylase, starch synthase and starch branching enzyme in grains. Our results indicate that water-saving irrigation by controlling limiting values of soil water potential related to specific growth stages can enhance physiological activities of roots and grains, reduce water input, and increase grain yield.
文摘Plant hormones regulate many aspects of plant growth and development. Both auxin and cytokinin have been known for a long time to act either synergistically or antagonistically to control several significant developmental processes, such as the formation and maintenance of meristem. Over the past few years, exciting progress has been made to reveal the molecular mechanisms underlying the auxin-cytokinin action and interaction. In this review, we shall briefly discuss the major progress made in auxin and cytokinin biosynthesis, auxin transport, and auxin and cytokinin signaling. The frameworks for the complicated interaction of these two hormones in the control of shoot apical meristem and root apical meristem formation as well as their roles in in vitro organ regeneration are the major focus of this review.
文摘The seed_specific phaseolin promoter (Ph/P) was fused to an ipt gene, then was cloned to a plant expression vector containing a gus gene driven by a 35S promoter. Cotton (Gossypium hirsutum L.) plants were transformed through pollen tube pathway methods. After seed germination, histochemical staining of the roots demonstrated that 32 GUS positive plants were obtained and three of which contained the chimeric Ph/P_ ipt transgene as confirmed by PCR analysis. An immunosorbent assay showed that two of the three transgenic cotton lines contained higher levels of zeatin equivalents in seeds than the control. Seedling development of these two transgenic lines differed from the control in a reduction of the shoot growth, showing a stunted phenotype as expected, but a surprisingly developed root system with a 3-4 fold fast_growing lateral roots. In addition, fibers (seed_hairs) of the two transgenic cotton lines were considerably shorter than those of the control. These results indicate that genetic engineering may be used to manipulate the development of cotton plants, particularly cotton fibers.
