A four-year field experiment was conducted with two cultivars and four N rate to investigate the spatiotemporal characteristics of leaf senescence in maize after silking and its response to N fertilizer rates on them,...A four-year field experiment was conducted with two cultivars and four N rate to investigate the spatiotemporal characteristics of leaf senescence in maize after silking and its response to N fertilizer rates on them,as well as to reveal the differences in post-silking chlorophyll degradation between low-N-tolerant cultivars.The results showed that the order of leaf senescence after silking in maize was lower leaf>upper leaf>ear leaf,leaf tip>middle>base.Increasing N fertilizer down-regulated the expression of ZmCLH2 and ZmPPH in the leaves at 10-30 d after silking,reducing CLH and PPH activities,thereby delaying the leaf senescence.These effects were more prominent in low-N-sensitive cultivar Xianyu 508(XY508)than in low-N-tolerant cultivar Zhenghong 311(ZH311),especially in the lower leaves and leaf tip.Under low N condition,leaf yellowing and chlorophyll degradation occurred later and slower in ZH311 than in XY508.This resulted in a higher post-silking dry matter accumulation and grain yield in ZH311,which may be one of the important physiological bases of low nitrogen tolerant cultivars.Future research should focus on developing low-N-tolerant maize cultivars with slower leaf senescence near the ear after silking.展开更多
Phosphorus(Pi)plays a crucial role in the growth and development of plants.Membrane lipid regulation is one of the main mechanisms underlying plant adaptation to Pi deficiency.Previously,the high tolerance to low-Pi s...Phosphorus(Pi)plays a crucial role in the growth and development of plants.Membrane lipid regulation is one of the main mechanisms underlying plant adaptation to Pi deficiency.Previously,the high tolerance to low-Pi stress was justified in an elite line,MSDZ 109,which was obtained from Malus mandshurica.To better understand the mechanism underlying high adaptation to low-Pi stress,currently,lipidomic and transcriptomic analysis,as well as CRISPR/Cas9 and MmGDPD1-overexpressing methodologies were comprehensively integrated into a strategy for elucidating the high tolerance to low-Pi stress.Totally,770 differential metabolites were identified from the roots between the low-Pi and stress-free,belonging to 21 sub-classes of lipid compounds.Fatty acids(FA)constituted the predominant lipid component,accounting for approximately 50%-60%of the total lipids,and triglycerides(TAG)ranked the second,comprising around 12%of the total,consecutively followed by phosphatidylcholine(PC)and diacylglycerol(DAG)with approximately 10%and 8%of the total,respectively.The synchronous transcriptomic analysis revealed a significant up-regulation of genes related to glycerophospholipid and glycerolipid metabolism,specifically those(e.g.,MmGDPD1,MmDGDG1,MmMGDG1,MmSQDG,etc.)involved in phospholipid and galactosyl synthesis in response to low-Pi stress.GUS fusing reporter assay showed that MmGDPD1 promoter induced GUS gene expression and demonstrated initiation activity.Based on expression analysis,a dual-luciferase reporter assay,as well as yeast one-hybrid(Y1H)identification,MmPHR1 was justified to bind with the MmGDPD1 promoter and positively regulate plant tolerance to low-Pi stress.To further elucidate the role of MmGDPD1,CRISPR/Cas9 and MmGDPD1-overexpressing vectors were successfully introduced into apple(‘Royal Gala')calli.Interestingly,the MmGDPD1-KO line calli exhibited the remarkable decreases in the contents of phosphodiesterase(PDE),activity,as well as the contents of total Pi,and Pi in comparison with those of the wild type.Conversely,MmGDPD1-OE ones demonstrated the significant elevation in Pi accumulations,further justifying its potential role in Pi remobilization in apple.Therefore,MmGDPD1 substantially involves elevating low-Pi tolerance via promoting Pi release in M.mandshurica.展开更多
The synthesis of multimodal hierarchically porous materials is of great challenge by facile approach.Herein,we assemble BPO_(4) hollow spheres into macroscopic foam materials with multimodal hierarchically porous stru...The synthesis of multimodal hierarchically porous materials is of great challenge by facile approach.Herein,we assemble BPO_(4) hollow spheres into macroscopic foam materials with multimodal hierarchically porous structure by combining down-to-up process and Ostwald ripening effect.Tailored monolithic B_(2)O_(3)@BPO_(4) foams were obtained from a sticky hydrogel precursor by a one-step annealing process.The foam has the self-supporting frame of BPO_(4) hollow spheres with covering B_(2)O_(3) nanowires and shows excellent permeability and relatively high surface area due to hierarchical structure.The formation mechanism of monolithic B_(2)O_(3)@BPO_(4) foams mainly undergoes inflation,particle aggregation,and Ostwald ripening process.Monolithic foams exhibit superior catalytic activity in oxidation dehydrogenation of alkanes due to the sufficient exposure of active sites over the special frame structure.Furthermore,various monolithic functionalized BPO_(4) foam composites can be easily synthesized and exhibit superior performance in different applications including the oxidation of carbon monoxide,and the self-driven removal of organic pollutants.More interestingly,we also found the sticky hydrogel precursor possesses good heat shielding effect.This work provides a new insight for constructing multimodal hierarchically porous materials with the remaining superior property of nanoscale to cope with various challenges.展开更多
基金supported by the National Key Research and Development Program of China(2022YFD190160304 and 2018YFD0301206)Natural Science Foundation of Sichuan Province(2022NSFSC0013)Sichuan Provincial Maize Innovation Team Construction Project(SCCXTD-2023-02).
文摘A four-year field experiment was conducted with two cultivars and four N rate to investigate the spatiotemporal characteristics of leaf senescence in maize after silking and its response to N fertilizer rates on them,as well as to reveal the differences in post-silking chlorophyll degradation between low-N-tolerant cultivars.The results showed that the order of leaf senescence after silking in maize was lower leaf>upper leaf>ear leaf,leaf tip>middle>base.Increasing N fertilizer down-regulated the expression of ZmCLH2 and ZmPPH in the leaves at 10-30 d after silking,reducing CLH and PPH activities,thereby delaying the leaf senescence.These effects were more prominent in low-N-sensitive cultivar Xianyu 508(XY508)than in low-N-tolerant cultivar Zhenghong 311(ZH311),especially in the lower leaves and leaf tip.Under low N condition,leaf yellowing and chlorophyll degradation occurred later and slower in ZH311 than in XY508.This resulted in a higher post-silking dry matter accumulation and grain yield in ZH311,which may be one of the important physiological bases of low nitrogen tolerant cultivars.Future research should focus on developing low-N-tolerant maize cultivars with slower leaf senescence near the ear after silking.
基金supported by grants from the National Guidance Foundation for Local Science and Technology Development of China(Grant No.2023-009)the Department of Science and Technology of Guizhou Province(Grant No.qiankehezhicheng-[2020]1Y025)。
文摘Phosphorus(Pi)plays a crucial role in the growth and development of plants.Membrane lipid regulation is one of the main mechanisms underlying plant adaptation to Pi deficiency.Previously,the high tolerance to low-Pi stress was justified in an elite line,MSDZ 109,which was obtained from Malus mandshurica.To better understand the mechanism underlying high adaptation to low-Pi stress,currently,lipidomic and transcriptomic analysis,as well as CRISPR/Cas9 and MmGDPD1-overexpressing methodologies were comprehensively integrated into a strategy for elucidating the high tolerance to low-Pi stress.Totally,770 differential metabolites were identified from the roots between the low-Pi and stress-free,belonging to 21 sub-classes of lipid compounds.Fatty acids(FA)constituted the predominant lipid component,accounting for approximately 50%-60%of the total lipids,and triglycerides(TAG)ranked the second,comprising around 12%of the total,consecutively followed by phosphatidylcholine(PC)and diacylglycerol(DAG)with approximately 10%and 8%of the total,respectively.The synchronous transcriptomic analysis revealed a significant up-regulation of genes related to glycerophospholipid and glycerolipid metabolism,specifically those(e.g.,MmGDPD1,MmDGDG1,MmMGDG1,MmSQDG,etc.)involved in phospholipid and galactosyl synthesis in response to low-Pi stress.GUS fusing reporter assay showed that MmGDPD1 promoter induced GUS gene expression and demonstrated initiation activity.Based on expression analysis,a dual-luciferase reporter assay,as well as yeast one-hybrid(Y1H)identification,MmPHR1 was justified to bind with the MmGDPD1 promoter and positively regulate plant tolerance to low-Pi stress.To further elucidate the role of MmGDPD1,CRISPR/Cas9 and MmGDPD1-overexpressing vectors were successfully introduced into apple(‘Royal Gala')calli.Interestingly,the MmGDPD1-KO line calli exhibited the remarkable decreases in the contents of phosphodiesterase(PDE),activity,as well as the contents of total Pi,and Pi in comparison with those of the wild type.Conversely,MmGDPD1-OE ones demonstrated the significant elevation in Pi accumulations,further justifying its potential role in Pi remobilization in apple.Therefore,MmGDPD1 substantially involves elevating low-Pi tolerance via promoting Pi release in M.mandshurica.
基金supported by the National Natural Science Foundation of China(No.22072024).
文摘The synthesis of multimodal hierarchically porous materials is of great challenge by facile approach.Herein,we assemble BPO_(4) hollow spheres into macroscopic foam materials with multimodal hierarchically porous structure by combining down-to-up process and Ostwald ripening effect.Tailored monolithic B_(2)O_(3)@BPO_(4) foams were obtained from a sticky hydrogel precursor by a one-step annealing process.The foam has the self-supporting frame of BPO_(4) hollow spheres with covering B_(2)O_(3) nanowires and shows excellent permeability and relatively high surface area due to hierarchical structure.The formation mechanism of monolithic B_(2)O_(3)@BPO_(4) foams mainly undergoes inflation,particle aggregation,and Ostwald ripening process.Monolithic foams exhibit superior catalytic activity in oxidation dehydrogenation of alkanes due to the sufficient exposure of active sites over the special frame structure.Furthermore,various monolithic functionalized BPO_(4) foam composites can be easily synthesized and exhibit superior performance in different applications including the oxidation of carbon monoxide,and the self-driven removal of organic pollutants.More interestingly,we also found the sticky hydrogel precursor possesses good heat shielding effect.This work provides a new insight for constructing multimodal hierarchically porous materials with the remaining superior property of nanoscale to cope with various challenges.
