The microscopic and ultrastructural characteristics of mesophyll cells in flag leaves of two rice lines （a thermosensitive line 4628 and a thermo-resistant line 996） under high temperature stress （37℃ during 8：00...The microscopic and ultrastructural characteristics of mesophyll cells in flag leaves of two rice lines （a thermosensitive line 4628 and a thermo-resistant line 996） under high temperature stress （37℃ during 8：00-17：00 and 30℃ during 17：00-8：00） were investigated using an optical and a transmission electron microscopy. The membrane permeability and malondialdehyde content increased under the high temperature stress, and the increase of both variables was greater in the line 4628 than in the line 996. Under the high temperature stress, the line 996 showed tightly arranged mesophyll cells in flag leaves, fully developed vascular bundles and some closed stomata, whereas the line 4628 suffered from injury because of undeveloped vascular bundles, loosely arranged mesophyll cells and opened stomata. The mesophyll cells in flag leaves of the line 4628 were severely damaged under the high temperature stress, i.e. the chloroplast envelope became blurred, the grana thylakoid layer was arranged loosely and irregularly, the stroma layer disappeared, many osmiophilic granules appeared within the chloroplast, the outer membrane of mitochondria and the nucleus disintegrated and became blurred, the nucleolus disappeared, and much fibrillar-granular materials appeared within the nucleus. In contrast, the mesophyll cells in flag leaves of the line 996 maintained an intact ultrastructure under the high temperature stress. From these results, it is suggested that the ultrastructural modification of the cell membrane system is the primary plant response to high temperature stress and can be used as an index to evaluate the crop heat tolerance.展开更多
Salinity is a serious threat to agricultural production. Potato （Solanum tuberosum） is an important food crop characterised for having low to moderate salinity tolerance. Tissue cultures may be relevant to improve s...Salinity is a serious threat to agricultural production. Potato （Solanum tuberosum） is an important food crop characterised for having low to moderate salinity tolerance. Tissue cultures may be relevant to improve salt tolerance in potato through selection of salt-tolerant cell lines and subsequent regeneration of plants. In this work, the authors used the random amplified polymorphic DNA （RAPD） markers to investigate the occurrence of genetic polymorphism in a potato calli line tolerant to 150 mM NaCI. Out of 40 primers screened, eight generated polymorphic patterns that distinguished salt-tolerant line from the control. Although the macroscopic appearance was similar in both lines, ultrastructural study revealed alterations in salt-grown cells. These showed that plastids less differentiated with a lower number of grana had more and larger starch grains than control cells. In conclusion, RAPD analysis revealed that NaCl-adapted line is a somaclonal variant and the ultrastructural study showed changes essentially at the plastids.展开更多
Objective:The aim of this study was to evaluate the value of contrast-enhanced ultrasound(CEUS) for blood perfusion of primary liver cancer(PHC) and investigate the correlation between microvascular architecture of PH...Objective:The aim of this study was to evaluate the value of contrast-enhanced ultrasound(CEUS) for blood perfusion of primary liver cancer(PHC) and investigate the correlation between microvascular architecture of PHC and pathological differentiation.Methods:Two hundred and seventy-eight patients with 329 PHC lesions were examined by CEUS and analysised the contrast enhancement pattern and correlation with pathology.Results:1.CEUS patterns of PHC:71.7%(236/329) showed "swift enhancement in the arterial phase and swift expurgation in the portal phase",13.4%(44/329) for as "swift enhancement and slow expurgation",7.3%(24/329) as "swift enhancement and simultaneity expurgation",4.3%(14/329) for the "slow enhancement and swift expurgation",2.1%(7/329) as "slow enhancement and expurgation",1.2%(4/329) as "not fast forward".2.90.3%(297/329) of PHC lesions were hypervascular liver cancer and 9.7%(32/329) were hypovascular.Hepatocellular carcinoma(HCC) were hypervascular lesions and intrahepatic cholangiocarcinoma(ICC) were hypovascular lesions.3.PHC size had a significant difference on the contrast media purfusion pattern(P < 0.05),but not on the contrast media expurgation pattern.4.The accuracy of PHC by CEUS were 97.3% and compared to pathology,9 lesions of PHC were misdiagnosed.Conclusion:CEUS can show the different blood perfusion characteristics of PHC with closely related to pathological differentiation,which be valuable to diagnose liver cancer.展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 30500315)the Agricultural Technological Results Transformation Item of Ministry of Agriculture, China (Grant No. 05EFN214300193)the Educational Foundation of Hunan Province, China (Grant No. 07C360)
文摘The microscopic and ultrastructural characteristics of mesophyll cells in flag leaves of two rice lines （a thermosensitive line 4628 and a thermo-resistant line 996） under high temperature stress （37℃ during 8：00-17：00 and 30℃ during 17：00-8：00） were investigated using an optical and a transmission electron microscopy. The membrane permeability and malondialdehyde content increased under the high temperature stress, and the increase of both variables was greater in the line 4628 than in the line 996. Under the high temperature stress, the line 996 showed tightly arranged mesophyll cells in flag leaves, fully developed vascular bundles and some closed stomata, whereas the line 4628 suffered from injury because of undeveloped vascular bundles, loosely arranged mesophyll cells and opened stomata. The mesophyll cells in flag leaves of the line 4628 were severely damaged under the high temperature stress, i.e. the chloroplast envelope became blurred, the grana thylakoid layer was arranged loosely and irregularly, the stroma layer disappeared, many osmiophilic granules appeared within the chloroplast, the outer membrane of mitochondria and the nucleus disintegrated and became blurred, the nucleolus disappeared, and much fibrillar-granular materials appeared within the nucleus. In contrast, the mesophyll cells in flag leaves of the line 996 maintained an intact ultrastructure under the high temperature stress. From these results, it is suggested that the ultrastructural modification of the cell membrane system is the primary plant response to high temperature stress and can be used as an index to evaluate the crop heat tolerance.
文摘Salinity is a serious threat to agricultural production. Potato （Solanum tuberosum） is an important food crop characterised for having low to moderate salinity tolerance. Tissue cultures may be relevant to improve salt tolerance in potato through selection of salt-tolerant cell lines and subsequent regeneration of plants. In this work, the authors used the random amplified polymorphic DNA （RAPD） markers to investigate the occurrence of genetic polymorphism in a potato calli line tolerant to 150 mM NaCI. Out of 40 primers screened, eight generated polymorphic patterns that distinguished salt-tolerant line from the control. Although the macroscopic appearance was similar in both lines, ultrastructural study revealed alterations in salt-grown cells. These showed that plastids less differentiated with a lower number of grana had more and larger starch grains than control cells. In conclusion, RAPD analysis revealed that NaCl-adapted line is a somaclonal variant and the ultrastructural study showed changes essentially at the plastids.
文摘Objective:The aim of this study was to evaluate the value of contrast-enhanced ultrasound(CEUS) for blood perfusion of primary liver cancer(PHC) and investigate the correlation between microvascular architecture of PHC and pathological differentiation.Methods:Two hundred and seventy-eight patients with 329 PHC lesions were examined by CEUS and analysised the contrast enhancement pattern and correlation with pathology.Results:1.CEUS patterns of PHC:71.7%(236/329) showed "swift enhancement in the arterial phase and swift expurgation in the portal phase",13.4%(44/329) for as "swift enhancement and slow expurgation",7.3%(24/329) as "swift enhancement and simultaneity expurgation",4.3%(14/329) for the "slow enhancement and swift expurgation",2.1%(7/329) as "slow enhancement and expurgation",1.2%(4/329) as "not fast forward".2.90.3%(297/329) of PHC lesions were hypervascular liver cancer and 9.7%(32/329) were hypovascular.Hepatocellular carcinoma(HCC) were hypervascular lesions and intrahepatic cholangiocarcinoma(ICC) were hypovascular lesions.3.PHC size had a significant difference on the contrast media purfusion pattern(P < 0.05),but not on the contrast media expurgation pattern.4.The accuracy of PHC by CEUS were 97.3% and compared to pathology,9 lesions of PHC were misdiagnosed.Conclusion:CEUS can show the different blood perfusion characteristics of PHC with closely related to pathological differentiation,which be valuable to diagnose liver cancer.
