To decipher the relationship between the inhibited shoot growth and expression pattern of key enzymes in nitrogen metabolism under root restriction, the effects of root restriction on diurnal variation of expression o...To decipher the relationship between the inhibited shoot growth and expression pattern of key enzymes in nitrogen metabolism under root restriction, the effects of root restriction on diurnal variation of expression of nitrate reductase （NR）, nitrite reductase （NiR）, glutamine synthetase （GSI-1, GS1-2, GS2） and glutamate synthase （Fd-GOGAT, NADH-GOGAT） genes and nitrogen levels were evaluated in two-year-old Jumeigui grapevines （Vitis vinifera L.xVitis labrusca L.） when significant differences in shoot growth were observed between treatments at expansion stage （22 days after anthesis）. Grapevines were planted in root-restricting pits as root restriction and in an unrestricted field as the control. Results showed that root restriction significantly reduced shoot growth, but promoted the growth of white roots and fibrous brown roots and improved the fruit quality. （NO3-＋NO2-）-N concentration in all plant parts, NH4＋-N concentration in white roots and total N concentration in leaves and brown roots were significantly reduced under root restriction. Gene expression analysis revealed that mRNA levels of genes related to the GS1/NADH-GOGAT pathway were lower in root-restricted than in control petioles, whereas genes involved in the GS2/Fd-GOGAT pathway were up-regulated under root restriction. Root restriction also resulted in downregulation of genes involved in nitrogen metabolism in leaves, especially at 10：00, while transcript levels of all these genes were enhanced in root-restricted white and brown roots at most time points. This organ-dependent response contributed to the alteration in NO3- reduction and NH4＋ assimilation under root restriction, leading to less NO3- transported from roots and then assimilated in root-restricted leaves. Therefore, this study implied that shoot growth inhibition in grapevines under root restriction is closely associated with down-regulation of gene expression in nitrogen metabolism in leaves.展开更多
To study the physiological effects of small root zonel plants of a hybrid wheat variety (Triticum aestivnmL.cv. Meiyou 4) were grown in small pots (1 litre) or large pots (8 litre) with 1ow nitrogen (50 mg kg-1 soil)a...To study the physiological effects of small root zonel plants of a hybrid wheat variety (Triticum aestivnmL.cv. Meiyou 4) were grown in small pots (1 litre) or large pots (8 litre) with 1ow nitrogen (50 mg kg-1 soil)and high nitrogen (200 mg kg-1 soil). Restricting root zone decreased dry weight of plants at the stages ofstem elongation and flowering, compared to those of control plants grown in the large pots (P<0.01). Sprayingof 6-benzylaminopurine (50 μmol L-1) increased dry weight of plants and chlorop hyll concentration in leaves.Restriction of root zone decreased the concentrations of total nitrogen, chlorophyll and soluble protein in thefiag leaf and acce1erated senescence of the leaves. Supply of high nitrogen delayed senescence of the fiag leafThe results suggested that the shortage of nutrients, especially nitrogen deficiency was the primary reasonfor the decreased growth of plant in the treatment of root zone restriction.展开更多
The aims of this work were to study the effect of two different plastic containers on asparagus growth and the effect of early applied 6-benzilaminepurine （BAP） on crown growth during the first two years after seed ...The aims of this work were to study the effect of two different plastic containers on asparagus growth and the effect of early applied 6-benzilaminepurine （BAP） on crown growth during the first two years after seed germination. Although there was not found a root restriction effect with the use of plastic containers, there were significant differences between plants grown in plastic seedbed or single pots which suggesting an unusual and unexpected asparagus autotoxicity. The results showed that crown fresh weight, total dry weight, relative growth ratio （RGRroot）, root：shoot ratio and photosynthetic shoot number increased in BAP-sprayed plants over the controls without treatment as a result of a change in photosynthate partitioning towards the root system. The BAP snravs seem to be a ~reater effect under conditions with favor autotoxicitv such as the seedbed than in single pot crown-grown.展开更多
A greenhouse experiment was conducted involving complete/intact 100 cm cores of a fragipan soil. The cores were maintained in moist conditions throughout the experiment as annual ryegrass (Lolium multiflorum) or festu...A greenhouse experiment was conducted involving complete/intact 100 cm cores of a fragipan soil. The cores were maintained in moist conditions throughout the experiment as annual ryegrass (Lolium multiflorum) or festulolium (Lolium spp and Fescue spp hybrid) were grown with and without additional surface applied amendments, including NaF, NaNO3, NaCl, and KCl. The results suggest a significant effect of annual ryegrass and festulolium on fragipan horizon degradation after 24 months. Annual ryegrass and festulolium were found to effectively change the structure of the fragipan horizon when planted on the soil surface and roots grew through the upper soil profile and penetrated into the fragipan. The fragipan structural change (degradation) appeared to increase with each planting sequence, particularly with soybean crop rotations. Sodium nitrate added to the soil surface with the growth of annual ryegrass resulted in a significant synergistic effect for degrading the fragipan horizon. The other amendments were not as effective in causing additional fragipan degradation.展开更多
The author explores the relationship between the cut locus of an arbitrary simply connected and compact Riemannian symmetric space and the Cartan polyhedron of corresponding restricted root system,and computes the inj...The author explores the relationship between the cut locus of an arbitrary simply connected and compact Riemannian symmetric space and the Cartan polyhedron of corresponding restricted root system,and computes the injectivity radius and diameter for every type of irreducible ones.展开更多
基金supported by the National Natural Science Foundation of China (30871695)
文摘To decipher the relationship between the inhibited shoot growth and expression pattern of key enzymes in nitrogen metabolism under root restriction, the effects of root restriction on diurnal variation of expression of nitrate reductase （NR）, nitrite reductase （NiR）, glutamine synthetase （GSI-1, GS1-2, GS2） and glutamate synthase （Fd-GOGAT, NADH-GOGAT） genes and nitrogen levels were evaluated in two-year-old Jumeigui grapevines （Vitis vinifera L.xVitis labrusca L.） when significant differences in shoot growth were observed between treatments at expansion stage （22 days after anthesis）. Grapevines were planted in root-restricting pits as root restriction and in an unrestricted field as the control. Results showed that root restriction significantly reduced shoot growth, but promoted the growth of white roots and fibrous brown roots and improved the fruit quality. （NO3-＋NO2-）-N concentration in all plant parts, NH4＋-N concentration in white roots and total N concentration in leaves and brown roots were significantly reduced under root restriction. Gene expression analysis revealed that mRNA levels of genes related to the GS1/NADH-GOGAT pathway were lower in root-restricted than in control petioles, whereas genes involved in the GS2/Fd-GOGAT pathway were up-regulated under root restriction. Root restriction also resulted in downregulation of genes involved in nitrogen metabolism in leaves, especially at 10：00, while transcript levels of all these genes were enhanced in root-restricted white and brown roots at most time points. This organ-dependent response contributed to the alteration in NO3- reduction and NH4＋ assimilation under root restriction, leading to less NO3- transported from roots and then assimilated in root-restricted leaves. Therefore, this study implied that shoot growth inhibition in grapevines under root restriction is closely associated with down-regulation of gene expression in nitrogen metabolism in leaves.
文摘To study the physiological effects of small root zonel plants of a hybrid wheat variety (Triticum aestivnmL.cv. Meiyou 4) were grown in small pots (1 litre) or large pots (8 litre) with 1ow nitrogen (50 mg kg-1 soil)and high nitrogen (200 mg kg-1 soil). Restricting root zone decreased dry weight of plants at the stages ofstem elongation and flowering, compared to those of control plants grown in the large pots (P<0.01). Sprayingof 6-benzylaminopurine (50 μmol L-1) increased dry weight of plants and chlorop hyll concentration in leaves.Restriction of root zone decreased the concentrations of total nitrogen, chlorophyll and soluble protein in thefiag leaf and acce1erated senescence of the leaves. Supply of high nitrogen delayed senescence of the fiag leafThe results suggested that the shortage of nutrients, especially nitrogen deficiency was the primary reasonfor the decreased growth of plant in the treatment of root zone restriction.
文摘The aims of this work were to study the effect of two different plastic containers on asparagus growth and the effect of early applied 6-benzilaminepurine （BAP） on crown growth during the first two years after seed germination. Although there was not found a root restriction effect with the use of plastic containers, there were significant differences between plants grown in plastic seedbed or single pots which suggesting an unusual and unexpected asparagus autotoxicity. The results showed that crown fresh weight, total dry weight, relative growth ratio （RGRroot）, root：shoot ratio and photosynthetic shoot number increased in BAP-sprayed plants over the controls without treatment as a result of a change in photosynthate partitioning towards the root system. The BAP snravs seem to be a ~reater effect under conditions with favor autotoxicitv such as the seedbed than in single pot crown-grown.
文摘A greenhouse experiment was conducted involving complete/intact 100 cm cores of a fragipan soil. The cores were maintained in moist conditions throughout the experiment as annual ryegrass (Lolium multiflorum) or festulolium (Lolium spp and Fescue spp hybrid) were grown with and without additional surface applied amendments, including NaF, NaNO3, NaCl, and KCl. The results suggest a significant effect of annual ryegrass and festulolium on fragipan horizon degradation after 24 months. Annual ryegrass and festulolium were found to effectively change the structure of the fragipan horizon when planted on the soil surface and roots grew through the upper soil profile and penetrated into the fragipan. The fragipan structural change (degradation) appeared to increase with each planting sequence, particularly with soybean crop rotations. Sodium nitrate added to the soil surface with the growth of annual ryegrass resulted in a significant synergistic effect for degrading the fragipan horizon. The other amendments were not as effective in causing additional fragipan degradation.
基金Project supported by the National Natural Science Foundation of China(No.10531090).
文摘The author explores the relationship between the cut locus of an arbitrary simply connected and compact Riemannian symmetric space and the Cartan polyhedron of corresponding restricted root system,and computes the injectivity radius and diameter for every type of irreducible ones.
