Lodging is a major problem limiting maize yield worldwide. However, the mechanisms of lodging resistance remain incompletely understood for maize. Here, we evaluated 443 maize accessions for lodging resistance in the ...Lodging is a major problem limiting maize yield worldwide. However, the mechanisms of lodging resistance remain incompletely understood for maize. Here, we evaluated 443 maize accessions for lodging resistance in the field. Five lodging-resistant accessions and five lodging-sensitive accessions were selected for further research. The leaf number, plant height, stem diameter, and rind penetrometer resistance were similar between lodging-resistant and-sensitive inbred lines. The average thickness of sclerenchymatous hypodermis layer was thicker and the vascular area was larger in the lodging-resistant lines compared with lodging-sensitive lines. Although total lignin content in stem tissue did not significantly differ between lodging-resistant and-sensitive lines, phloroglucinol staining revealed that the lignin content of the cell wall in the stem cortex and in the stem vascular tissue near the cortex was higher in the lodging-resistant lines than in the lodging-sensitive lines. Analysis of strand-specific RNA-seq transcriptome showed that a total of 793 genes were up-regulated and 713 genes were down-regulated in lodging-resistant lines relative to lodging-sensitive lines. The up-regulated genes in lodging-resistant lines were enriched in cell wall biogenesis. These results indicated that modification of cell wall biosynthesis would contribute to lodging resistance of maize.展开更多
Plant cell walls constitute the skeletal structures of plant bodies,and thus confer lodging resistance for grain crops.While the basic cell wall synthesis machinery is relatively well established now,our understanding...Plant cell walls constitute the skeletal structures of plant bodies,and thus confer lodging resistance for grain crops.While the basic cell wall synthesis machinery is relatively well established now,our understanding of how the process is regulated remains limited and fragmented.In this study,we report the identification and characterization of the novel rice（Oryza sativa L.）brittle culm16（brittle node;bc16）mutant.The brittle node phenotype of the bc16 mutant appears exclusively at nodes,and resembles the previously reported bc5 mutant.Combined histochemical staining and electron microscopy assays revealed that in the bc16 mutant,the secondary cell wall formation and thickening of node sclerenchyma tissues are seriously affected after heading.Furthermore,cell wall composition assays revealed that the bc16 mutation led to a significant reduction in cellulose and lignin contents.Using a map-based cloning approach,the bc16 locus is mapped to an approximately 1.7-Mb region of chromosome 4.Together,our findings strengthen evidence for discretely spatial differences in the secondary cell wall formation within plant bodies.展开更多
Erianthus species are perennial C4 grasses with such high biomass productivity and high tolerance to environmental stresses that they can be grown in marginal land to supply raw material for cellulosic bioethanol. Bec...Erianthus species are perennial C4 grasses with such high biomass productivity and high tolerance to environmental stresses that they can be grown in marginal land to supply raw material for cellulosic bioethanol. Because high biomass production and strong tolerance to environmental stresses might be based on their large and deep-root system, we closely examined the morphology and anatomy of roots in first-year seedlings of field-grown Erianthus arundinaceus. The deep-root system of E. arundinaceus consists of many nodal roots growing with steep growth angles. Diameter of nodal roots with large variations (0.5 - 5 mm) correlates with the size and number of large xylem vessels. The microscopic observation shows that the nodal roots with dense root hairs developed soil sheath, hypodermis with lignified sclerenchyma in the outer cortex, and aerenchyma in the mid-cortex. In addition, starch grains were densely accumulated in the stele of nodal roots in winter. In the first year, E. arundinaceus developed less lateral roots than other reported grass species. The lateral roots formed a large xylem vessel in the center of the stele and no hypodermis in the outer cortex. Morphology and anatomy of E. arundinaceus root were discussed with reference to strong tolerance to environmental stresses.展开更多
基金supported by National Natural Science Foundation of China(31861143004)the National Key Research and Development Program of China(2016YFD0100701)the Agricultural Science and Technology Innovation Program of CAAS to WXL。
文摘Lodging is a major problem limiting maize yield worldwide. However, the mechanisms of lodging resistance remain incompletely understood for maize. Here, we evaluated 443 maize accessions for lodging resistance in the field. Five lodging-resistant accessions and five lodging-sensitive accessions were selected for further research. The leaf number, plant height, stem diameter, and rind penetrometer resistance were similar between lodging-resistant and-sensitive inbred lines. The average thickness of sclerenchymatous hypodermis layer was thicker and the vascular area was larger in the lodging-resistant lines compared with lodging-sensitive lines. Although total lignin content in stem tissue did not significantly differ between lodging-resistant and-sensitive lines, phloroglucinol staining revealed that the lignin content of the cell wall in the stem cortex and in the stem vascular tissue near the cortex was higher in the lodging-resistant lines than in the lodging-sensitive lines. Analysis of strand-specific RNA-seq transcriptome showed that a total of 793 genes were up-regulated and 713 genes were down-regulated in lodging-resistant lines relative to lodging-sensitive lines. The up-regulated genes in lodging-resistant lines were enriched in cell wall biogenesis. These results indicated that modification of cell wall biosynthesis would contribute to lodging resistance of maize.
基金supported by the Fundamental Research Funds for Excellent Young Scientists of Institute of Crop Sciences, Chinese Academy of Agricultural Sciences (Grant to YR, 2014JB04-009, 1610092015003-08)the National Transgenic Science and Technology Program, China (2016ZX08009003-003)
文摘Plant cell walls constitute the skeletal structures of plant bodies,and thus confer lodging resistance for grain crops.While the basic cell wall synthesis machinery is relatively well established now,our understanding of how the process is regulated remains limited and fragmented.In this study,we report the identification and characterization of the novel rice（Oryza sativa L.）brittle culm16（brittle node;bc16）mutant.The brittle node phenotype of the bc16 mutant appears exclusively at nodes,and resembles the previously reported bc5 mutant.Combined histochemical staining and electron microscopy assays revealed that in the bc16 mutant,the secondary cell wall formation and thickening of node sclerenchyma tissues are seriously affected after heading.Furthermore,cell wall composition assays revealed that the bc16 mutation led to a significant reduction in cellulose and lignin contents.Using a map-based cloning approach,the bc16 locus is mapped to an approximately 1.7-Mb region of chromosome 4.Together,our findings strengthen evidence for discretely spatial differences in the secondary cell wall formation within plant bodies.
文摘Erianthus species are perennial C4 grasses with such high biomass productivity and high tolerance to environmental stresses that they can be grown in marginal land to supply raw material for cellulosic bioethanol. Because high biomass production and strong tolerance to environmental stresses might be based on their large and deep-root system, we closely examined the morphology and anatomy of roots in first-year seedlings of field-grown Erianthus arundinaceus. The deep-root system of E. arundinaceus consists of many nodal roots growing with steep growth angles. Diameter of nodal roots with large variations (0.5 - 5 mm) correlates with the size and number of large xylem vessels. The microscopic observation shows that the nodal roots with dense root hairs developed soil sheath, hypodermis with lignified sclerenchyma in the outer cortex, and aerenchyma in the mid-cortex. In addition, starch grains were densely accumulated in the stele of nodal roots in winter. In the first year, E. arundinaceus developed less lateral roots than other reported grass species. The lateral roots formed a large xylem vessel in the center of the stele and no hypodermis in the outer cortex. Morphology and anatomy of E. arundinaceus root were discussed with reference to strong tolerance to environmental stresses.
