As the most important organ in plant photosynthesis, the leaf plays an important role in plant growth and development. Leaf senescence is associated with fundamental changes in the proteome. To research the molecular ...As the most important organ in plant photosynthesis, the leaf plays an important role in plant growth and development. Leaf senescence is associated with fundamental changes in the proteome. To research the molecular mechanisms of leaf senescence, protein expression in senescing maize ear leaves grown under field conditions was analyzed using two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionisation time-of-flight/time-of-flight mass spectrometry（MALDI-TOF/TOF MS）. A total of 60 senescence-associated proteins were identified. The identified proteins are involved in many biological processes, especially energy, metabolism and protein synthesis. Several of the identified proteins have not been previously reported as senescence-associated, including glycine-rich RNA-binding protein.展开更多
Nitrogen concentration in the ear leaf is a good indicator of corn (Zea mays L.) N nutrition status during late growing season. This study was done to examine the relationship of late-season ear leaf N concentration w...Nitrogen concentration in the ear leaf is a good indicator of corn (Zea mays L.) N nutrition status during late growing season. This study was done to examine the relationship of late-season ear leaf N concentration with early- to mid- season plant height of corn at Milan, TN from 2008 to 2010 using linear, quadratic, square root, logarithmic, and exponential models. Six N rate treatments (0, 62, 123, 185, 247, and 308 kg·N·ha-1) repeated four times were implemented each year in a randomized complete block design under four major cropping systems: corn after corn, corn after soybean [Glycine max (L.) Merr.], corn after cotton [Gossypium hirsutum (L.)], and irrigated corn after soybean. The relationship of ear leaf N concentration determined at the blister growth stage (R2) with plant height measured at the 6-leaf (V6), 10-leaf (V10), and 12-leaf (V12) growth stages was statistically significant and positive in non-irrigated corn under normal weather conditions. However, the strength of this relationship was weak to moderate with the determination coefficient (R2) values ranging from 0.21 to 0.51. This relationship was generally improved as the growing season progressed from V6 to V12. Irrigation and abnormal weather seemed to have adverse effects on this relationship. The five regression models performed similarly in the evaluation of this relationship regardless of growth stage, year, and cropping system. Our results suggest that unlike the relationship of corn yield at harvest with plant height measured during early- to mid-season or the relationship of leaf N concentration with plant height when both are measured simultaneously during early- to mid-season, the relationship of late-season ear leaf N concentration with early- to mid-season plant height may not be strong enough to be used to develop algorithms for variable-rate N applications on corn within a field no matter which regression model is used to describe this relationship.展开更多
基金supports from the National Natural Science Foundation of China (31171497)the National Basic Research Program of China (973 Program, 2011CB100105)+1 种基金the Corn Industry Technology System, Ministry of Agriculture, China (CARS-02)the Special Fund for Agro-scientific Research in the Public Interest, China (201203096, 201203100)
文摘As the most important organ in plant photosynthesis, the leaf plays an important role in plant growth and development. Leaf senescence is associated with fundamental changes in the proteome. To research the molecular mechanisms of leaf senescence, protein expression in senescing maize ear leaves grown under field conditions was analyzed using two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionisation time-of-flight/time-of-flight mass spectrometry（MALDI-TOF/TOF MS）. A total of 60 senescence-associated proteins were identified. The identified proteins are involved in many biological processes, especially energy, metabolism and protein synthesis. Several of the identified proteins have not been previously reported as senescence-associated, including glycine-rich RNA-binding protein.
文摘Nitrogen concentration in the ear leaf is a good indicator of corn (Zea mays L.) N nutrition status during late growing season. This study was done to examine the relationship of late-season ear leaf N concentration with early- to mid- season plant height of corn at Milan, TN from 2008 to 2010 using linear, quadratic, square root, logarithmic, and exponential models. Six N rate treatments (0, 62, 123, 185, 247, and 308 kg·N·ha-1) repeated four times were implemented each year in a randomized complete block design under four major cropping systems: corn after corn, corn after soybean [Glycine max (L.) Merr.], corn after cotton [Gossypium hirsutum (L.)], and irrigated corn after soybean. The relationship of ear leaf N concentration determined at the blister growth stage (R2) with plant height measured at the 6-leaf (V6), 10-leaf (V10), and 12-leaf (V12) growth stages was statistically significant and positive in non-irrigated corn under normal weather conditions. However, the strength of this relationship was weak to moderate with the determination coefficient (R2) values ranging from 0.21 to 0.51. This relationship was generally improved as the growing season progressed from V6 to V12. Irrigation and abnormal weather seemed to have adverse effects on this relationship. The five regression models performed similarly in the evaluation of this relationship regardless of growth stage, year, and cropping system. Our results suggest that unlike the relationship of corn yield at harvest with plant height measured during early- to mid-season or the relationship of leaf N concentration with plant height when both are measured simultaneously during early- to mid-season, the relationship of late-season ear leaf N concentration with early- to mid-season plant height may not be strong enough to be used to develop algorithms for variable-rate N applications on corn within a field no matter which regression model is used to describe this relationship.
