The incorporation of xyloglucan oligosaccharide （XXXG） into the walls of suspension-cultured tobacco cells accelerated cell expansion followed by cell division, changed cell shape from cylindrical to spherical, decr...The incorporation of xyloglucan oligosaccharide （XXXG） into the walls of suspension-cultured tobacco cells accelerated cell expansion followed by cell division, changed cell shape from cylindrical to spherical, decreased cell size, and caused cell aggregation. Fluorescent XXXG added to the culture medium was found to be incorporated into the surface of the entire wall, where strong incorporation occurred not only on the surface, but also in the interface walls between cells during cell division. Cell expansion was always greater in the transverse direction than in the longitudinal direction and then, immediately, expansion led to cell division in the presence of XXXG; this process might result in the high level of cell aggregation seen in cultured tobacco cells. We concluded that the integration of this oligosaccharide into the walls could accelerate not only cell expansion, but also cell division in cultured cells.展开更多
The microtubule preprophase bands （PPBs） participate in the sequence of events to position cell plates in most plants. However, the mechanism of PPB formation remains to be clarified. In the present study, the organ...The microtubule preprophase bands （PPBs） participate in the sequence of events to position cell plates in most plants. However, the mechanism of PPB formation remains to be clarified. In the present study, the organization of PPBs in Arabidopsis suspension cultured cells was investigated by confocal laser scanning microscopy combined with pharmacological treatments of reagents specific for the cytoskeleton elements. Double staining of F-actin and microtubules （MTs） showed that actin filaments were arranged randomly and no colocalization with cortical MTs was observed in the interphase cells. However, cortical actin filaments showed colocalization with MTs during the formation of PPBs. A broad actin band formed with the broad MT band in the initiation of PPB and narrowed down together with the MT band to form the PPB. Nevertheless, broad MT bands were formed but failed to narrow down in cells treated with the F-actin disruptor latrunculin A. In contrast, in the presence of the F-actin stabilizer phalloidin, PPB formation did not exhibit any abnormality. Therefore, the integrity, but not the dynamics, of the actin cytoskeleton is necessary for the formation of normal PPBs. Treatment with 2, 3-butanedine monoxime, a myosin inhibitor, also resulted in the formation of broad MT bands, indicating that actomyosin may be involved in the rearrangement of MTs to form the PPBs. Double staining of MTs and myosin revealed that myosin concentrated on the PPB region during PPB formation. It is suggested that the actin cytoskeleton at the PPB site may serve as a rack to transport cortical MTs by using myosin when the broad MT band narrows down to form the PPB.展开更多
Plant regeneration from protoplasts offers a unique and essential system for genetic manipulation in cereals. The genetic manipulation was limited to some extent owing to the difficulty in plant regeneration from prot...Plant regeneration from protoplasts offers a unique and essential system for genetic manipulation in cereals. The genetic manipulation was limited to some extent owing to the difficulty in plant regeneration from protoplasts in crops. In recent years the successful regeneration from protoplasts of rice has been reported. In this work, the high dividing frequency and plant regeneration of indica rice are reported.展开更多
The cell suspension cultures in leaves of Pueraria lobata (Willd.) Ohwi seedlings were treated with salicylic acid (SA), methyl jasmonate (MJ) and ethrel respectively. SA and MJ could cause cell brown, while ethre...The cell suspension cultures in leaves of Pueraria lobata (Willd.) Ohwi seedlings were treated with salicylic acid (SA), methyl jasmonate (MJ) and ethrel respectively. SA and MJ could cause cell brown, while ethrel had a positive effect on cell vitality. 0.1 mg/L SA and 1.0 mg/L MJ could promote the synthesis of puerarin and hence improved the yield. Ethrel, SA and MJ at higher concentrations restrained the product of puerarin. All these three substances had no effects on increasing cell biomass and puerarin release.展开更多
文摘The incorporation of xyloglucan oligosaccharide （XXXG） into the walls of suspension-cultured tobacco cells accelerated cell expansion followed by cell division, changed cell shape from cylindrical to spherical, decreased cell size, and caused cell aggregation. Fluorescent XXXG added to the culture medium was found to be incorporated into the surface of the entire wall, where strong incorporation occurred not only on the surface, but also in the interface walls between cells during cell division. Cell expansion was always greater in the transverse direction than in the longitudinal direction and then, immediately, expansion led to cell division in the presence of XXXG; this process might result in the high level of cell aggregation seen in cultured tobacco cells. We concluded that the integration of this oligosaccharide into the walls could accelerate not only cell expansion, but also cell division in cultured cells.
基金Supported by the State Key Basic Research and Development Plan of China （2006CB100101） and the National Natural Science Foundation of China （30421002, 30370707 and 30100091 ）.
文摘The microtubule preprophase bands （PPBs） participate in the sequence of events to position cell plates in most plants. However, the mechanism of PPB formation remains to be clarified. In the present study, the organization of PPBs in Arabidopsis suspension cultured cells was investigated by confocal laser scanning microscopy combined with pharmacological treatments of reagents specific for the cytoskeleton elements. Double staining of F-actin and microtubules （MTs） showed that actin filaments were arranged randomly and no colocalization with cortical MTs was observed in the interphase cells. However, cortical actin filaments showed colocalization with MTs during the formation of PPBs. A broad actin band formed with the broad MT band in the initiation of PPB and narrowed down together with the MT band to form the PPB. Nevertheless, broad MT bands were formed but failed to narrow down in cells treated with the F-actin disruptor latrunculin A. In contrast, in the presence of the F-actin stabilizer phalloidin, PPB formation did not exhibit any abnormality. Therefore, the integrity, but not the dynamics, of the actin cytoskeleton is necessary for the formation of normal PPBs. Treatment with 2, 3-butanedine monoxime, a myosin inhibitor, also resulted in the formation of broad MT bands, indicating that actomyosin may be involved in the rearrangement of MTs to form the PPBs. Double staining of MTs and myosin revealed that myosin concentrated on the PPB region during PPB formation. It is suggested that the actin cytoskeleton at the PPB site may serve as a rack to transport cortical MTs by using myosin when the broad MT band narrows down to form the PPB.
文摘Plant regeneration from protoplasts offers a unique and essential system for genetic manipulation in cereals. The genetic manipulation was limited to some extent owing to the difficulty in plant regeneration from protoplasts in crops. In recent years the successful regeneration from protoplasts of rice has been reported. In this work, the high dividing frequency and plant regeneration of indica rice are reported.
文摘The cell suspension cultures in leaves of Pueraria lobata (Willd.) Ohwi seedlings were treated with salicylic acid (SA), methyl jasmonate (MJ) and ethrel respectively. SA and MJ could cause cell brown, while ethrel had a positive effect on cell vitality. 0.1 mg/L SA and 1.0 mg/L MJ could promote the synthesis of puerarin and hence improved the yield. Ethrel, SA and MJ at higher concentrations restrained the product of puerarin. All these three substances had no effects on increasing cell biomass and puerarin release.
