Brittleness culm is an important agronomic trait that has a potential usefulness in agricultural activity as animal forage although the developmental mechanism is not clear yet. In the present study, the anatomical an...Brittleness culm is an important agronomic trait that has a potential usefulness in agricultural activity as animal forage although the developmental mechanism is not clear yet. In the present study, the anatomical and chemical characteristics as well as some ecophysiological features in the brittleness culm mutation of rice （Oryza sativa L.） were investigated. Compared with the wild type （WT）, the brittleness culm mutant （bcm） exhibited higher culm vascular bundle distance and lower culm wall thickness, leaf interveinal distance and leaf thickness. Ratio of bundle sheath cell/whole bundle and areas of whole vascular bundles and bundle sheath of leaves were reduced while ratios of xylem and phloem to whole bundles were elevated in bcm. The Fourier transform infrared （FTIR） microspectroscopy analysis and further histochemical and physiological measurements revealed that the different contents and depositions of cell wall components such as pectins, lignin, suberin and cellulose all participated in the mutation of brittleness. However, the mutant presented no significant changes in leaf photosynthetic dynamics and apoplastic transport ability. These results strongly indicate that the alterations in anatomical and chemical characteristics, rather than changes in major ecophysiological features such as photosynthesis and apoplastic transport were involved in the brittleness mutation of rice.展开更多
The anatomical and chemical characteristics of a rolling leaf mutant （rlm） of rice （Oryza sativa L.） and its ecophysiological properties in photosynthesis and apoplastic transport were investigated. Compared with ...The anatomical and chemical characteristics of a rolling leaf mutant （rlm） of rice （Oryza sativa L.） and its ecophysiological properties in photosynthesis and apoplastic transport were investigated. Compared with the wild type （WT）, the areas of whole vascular bundles and xylem as well as the ratios of xylem area/whole vascular bundles area and xylem area/phloem area were higher in rim, whereas the area and the width of foliar bulliform cell were lower. The Fourier transform infrared （FTIR） microspectroscopy spectra of foliar cell walls differed greatly between rim and WT. The rim exhibited lower protein and polysaccharide contents of foliar cell walls. An obvious reduction of pectin content was also found in rim by biochemical measurements. Moreover, the rate of photosynthesis was depressed while the conductance of stoma and the intercellular CO2 concentration were enhanced in rim. The PTS fluorescence, which represents the ability of apoplastic transport, was 11% higher in rim than in WT. These results suggest that the changes in anatomical and chemical characteristics of foliar vascular bundles, such as the reduction of proteins, pectins, and other polysaccharides of foliar cell walls, participate in the leaf rolling mutation, and consequently lead to the reduced photosynthetic dynamics and apoplastic transport ability in the mutant.展开更多
基金Supported by the National Natural Science Foundation of China (30470274)the Zhejiang Provincial Natural Science Foundation (Y306087)
文摘Brittleness culm is an important agronomic trait that has a potential usefulness in agricultural activity as animal forage although the developmental mechanism is not clear yet. In the present study, the anatomical and chemical characteristics as well as some ecophysiological features in the brittleness culm mutation of rice （Oryza sativa L.） were investigated. Compared with the wild type （WT）, the brittleness culm mutant （bcm） exhibited higher culm vascular bundle distance and lower culm wall thickness, leaf interveinal distance and leaf thickness. Ratio of bundle sheath cell/whole bundle and areas of whole vascular bundles and bundle sheath of leaves were reduced while ratios of xylem and phloem to whole bundles were elevated in bcm. The Fourier transform infrared （FTIR） microspectroscopy analysis and further histochemical and physiological measurements revealed that the different contents and depositions of cell wall components such as pectins, lignin, suberin and cellulose all participated in the mutation of brittleness. However, the mutant presented no significant changes in leaf photosynthetic dynamics and apoplastic transport ability. These results strongly indicate that the alterations in anatomical and chemical characteristics, rather than changes in major ecophysiological features such as photosynthesis and apoplastic transport were involved in the brittleness mutation of rice.
基金supported by the National Natural Science Foundation of China (Grant No. 30470274)the Zhejiang Natural Science Foundation of China (Grant No. Y306087)the Zijin Program of Zhejiang University for Young Teachers, China.
文摘The anatomical and chemical characteristics of a rolling leaf mutant （rlm） of rice （Oryza sativa L.） and its ecophysiological properties in photosynthesis and apoplastic transport were investigated. Compared with the wild type （WT）, the areas of whole vascular bundles and xylem as well as the ratios of xylem area/whole vascular bundles area and xylem area/phloem area were higher in rim, whereas the area and the width of foliar bulliform cell were lower. The Fourier transform infrared （FTIR） microspectroscopy spectra of foliar cell walls differed greatly between rim and WT. The rim exhibited lower protein and polysaccharide contents of foliar cell walls. An obvious reduction of pectin content was also found in rim by biochemical measurements. Moreover, the rate of photosynthesis was depressed while the conductance of stoma and the intercellular CO2 concentration were enhanced in rim. The PTS fluorescence, which represents the ability of apoplastic transport, was 11% higher in rim than in WT. These results suggest that the changes in anatomical and chemical characteristics of foliar vascular bundles, such as the reduction of proteins, pectins, and other polysaccharides of foliar cell walls, participate in the leaf rolling mutation, and consequently lead to the reduced photosynthetic dynamics and apoplastic transport ability in the mutant.
