Low-energy ion implantation, as a new technology to produce mutation in plant breeding, has been widely applied in agriculture in China. But so far there is a little understanding of the underlying mechanisms responsi...Low-energy ion implantation, as a new technology to produce mutation in plant breeding, has been widely applied in agriculture in China. But so far there is a little understanding of the underlying mechanisms responsible for its biological effects at the cellular level. Here we report the biological effects of a nitrogen ion beams of 30 keV on the pollen grains of Pinus thunbergii Parl. In general, ion implantation inhibited pollen germination. The dose-response curve presented a particular saddle-like pattern. Ion implantation also changed the dimension of the elongated tubes and significantly induced tip swelling. Confocal microscopy indicated that the pollen tube tips in P. thunbergii contained an enriched network of microtubules. Ion implantation led to the disruption of microtubules especially in swollen tips. Treatment with colchicine demonstrated that tip swelling was caused by the disruption of microtubules in the tip, indicating a unique role for microtubules in maintaining the tip integrality of the pollen tube in conifer. Our results suggest that ion implantation induce the disruption of microtubule organization in pollen and pollen tubes and subsequently cause morphological abnormalities in the pollen tubes. This study may provide a clue for further investigation on the interaction between low-energy ion beams and pollen tube growth.展开更多
为筛选并鉴定黑松和美味牛肝菌菌根生长的辅助细菌(MHB),进一步探明根际微生物互作关系及其互作对黑松生长的作用,通过分离黑松-美味牛肝菌根际细菌、检测其胞外代谢产物对美味牛肝菌(Be)菌丝生长的促进作用,筛选出MHB潜力菌株。以MHB...为筛选并鉴定黑松和美味牛肝菌菌根生长的辅助细菌(MHB),进一步探明根际微生物互作关系及其互作对黑松生长的作用,通过分离黑松-美味牛肝菌根际细菌、检测其胞外代谢产物对美味牛肝菌(Be)菌丝生长的促进作用,筛选出MHB潜力菌株。以MHB潜力菌株对松苗的苗高、地径、茎根比、根侵染率的影响,筛选出菌根辅助细菌。通过细菌的形态、生化特性、16S r DNA序列鉴定细菌的种类。结果表明,菌株H12代谢产物可以显著促进Be菌丝生长,双接种Be+H12的黑松苗,苗高提高23.5%,地径提高50.5%,根侵染率提高了472.9%,茎根比下降37.9%。经鉴定,确定菌株H12为蜂房类芽孢杆菌(Paenibacillus alvei)。蜂房类芽孢杆菌对菌根的促生作用明显,可进一步开发为菌塘微生物菌剂。展开更多
Pollen grains of Pinus thunbergii Parl. （Japanese black pine） were implanted with 30 keV nitrogen ion beams and the effects of nitrogen ion implantation on pollen tube growth in vitro and the organization of actin c...Pollen grains of Pinus thunbergii Parl. （Japanese black pine） were implanted with 30 keV nitrogen ion beams and the effects of nitrogen ion implantation on pollen tube growth in vitro and the organization of actin cytoskeleton in the pollen tube cell were investigated using a confocal laser scanning microscope after fluorescence labeling. Treatment with ion implantation significantly blocked pollen tube growth. Confocal microscopy showed that ion implantation disrupted actin filament cytoskeleton organization in the pollen tube. It was found that there was a distinct correlation between the inhibition of pollen tube growth and the disruption of actin cytoskeleton organization, indicating that an intact actin cytoskeleton is essential for continuous pollen tube elongation in Pinus thunbergii. Although the detailed mechanism for the ion-implantation-induced bioeffect still remains to be elucidated, the present study assumes that the cytoskeleton system in pollen grains may provide a key target in response to ion beam implantation and is involved in mediating certain subsequent cytological changes.展开更多
基金supported by National Key Project of China (No. 2001BA302B)
文摘Low-energy ion implantation, as a new technology to produce mutation in plant breeding, has been widely applied in agriculture in China. But so far there is a little understanding of the underlying mechanisms responsible for its biological effects at the cellular level. Here we report the biological effects of a nitrogen ion beams of 30 keV on the pollen grains of Pinus thunbergii Parl. In general, ion implantation inhibited pollen germination. The dose-response curve presented a particular saddle-like pattern. Ion implantation also changed the dimension of the elongated tubes and significantly induced tip swelling. Confocal microscopy indicated that the pollen tube tips in P. thunbergii contained an enriched network of microtubules. Ion implantation led to the disruption of microtubules especially in swollen tips. Treatment with colchicine demonstrated that tip swelling was caused by the disruption of microtubules in the tip, indicating a unique role for microtubules in maintaining the tip integrality of the pollen tube in conifer. Our results suggest that ion implantation induce the disruption of microtubule organization in pollen and pollen tubes and subsequently cause morphological abnormalities in the pollen tubes. This study may provide a clue for further investigation on the interaction between low-energy ion beams and pollen tube growth.
文摘为筛选并鉴定黑松和美味牛肝菌菌根生长的辅助细菌(MHB),进一步探明根际微生物互作关系及其互作对黑松生长的作用,通过分离黑松-美味牛肝菌根际细菌、检测其胞外代谢产物对美味牛肝菌(Be)菌丝生长的促进作用,筛选出MHB潜力菌株。以MHB潜力菌株对松苗的苗高、地径、茎根比、根侵染率的影响,筛选出菌根辅助细菌。通过细菌的形态、生化特性、16S r DNA序列鉴定细菌的种类。结果表明,菌株H12代谢产物可以显著促进Be菌丝生长,双接种Be+H12的黑松苗,苗高提高23.5%,地径提高50.5%,根侵染率提高了472.9%,茎根比下降37.9%。经鉴定,确定菌株H12为蜂房类芽孢杆菌(Paenibacillus alvei)。蜂房类芽孢杆菌对菌根的促生作用明显,可进一步开发为菌塘微生物菌剂。
基金National Science Foundation of Fujian Province of China(No.B0610031)Science and Technology Program of Put-Jan Municipality of China(No.2006N17)
文摘Pollen grains of Pinus thunbergii Parl. （Japanese black pine） were implanted with 30 keV nitrogen ion beams and the effects of nitrogen ion implantation on pollen tube growth in vitro and the organization of actin cytoskeleton in the pollen tube cell were investigated using a confocal laser scanning microscope after fluorescence labeling. Treatment with ion implantation significantly blocked pollen tube growth. Confocal microscopy showed that ion implantation disrupted actin filament cytoskeleton organization in the pollen tube. It was found that there was a distinct correlation between the inhibition of pollen tube growth and the disruption of actin cytoskeleton organization, indicating that an intact actin cytoskeleton is essential for continuous pollen tube elongation in Pinus thunbergii. Although the detailed mechanism for the ion-implantation-induced bioeffect still remains to be elucidated, the present study assumes that the cytoskeleton system in pollen grains may provide a key target in response to ion beam implantation and is involved in mediating certain subsequent cytological changes.
