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Cell Production and Expansion in the Primary Root of Maize in Response to Low-Nitrogen Stress

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Journal of Integrative Agriculture 2014年第11期13卷 2508-2517页

作者： GAO Kun CHEN Fan-jun yuan li-xing MI Guo-hua Key Laboratory of Plant-Soil Interaction Ministry of Agriculture/Center for Resources Environment and Food Security College of Resources and Environmental Sciences China Agricultural University

Maize plants respond to low-nitrogen stress by enhancing root elongation. The underlying physiological mechanism remains unknown. Seedlings of maize （Zea mays L., cv. Zhengdan 958） were grown in hydroponics with the control （4 mmol L-1） or low-nitrogen （40 μmol L-1） for 12 d, supplied as nitrate. Low nitrogen enhanced root elongation rate by 4.1-fold, accompanied by increases in cell production rate by 2.2-fold, maximal elemental elongation rate （by 2.5-fold）, the length of elongation zone （by 1.5-fold）, and ifnal cell length by 1.8-fold. On low nitrogen, the higher cell production rate resulted from a higher cell division rate and in fact the number of dividing cells was reduced. Consequently, the residence time of a cell in the division zone tended to be shorter under low nitrogen. In addition, low nitrogen increased root diameter, an increase that occurred speciifcally in the cortex and was accompanied by an increase in cell number. It is concluded that roots elongates in response to low-nitrogen stress by accelerating cell production and expansion.

关键词： cell length elemental expansion kinematic analysis root diameter root elongation Zea mays L

Phenotypic characterization and genetic mapping of the dwarf mutant m34 in maize

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Journal of Integrative Agriculture 2019年第5期18卷 948-957页

作者： li Jie-ping Soomro Ayaz Ali XIAO Gui CHEN Fan-jun yuan li-xing GU Ri-liang Lab of Plant-Soil Interaction Ministry of Agriculture/Department of Plant Nutrition College of Resources and Environmental Sciences China Agricultural University Center for Seed Science and Technology College of Agronomy and Biotechnology China Agricultural University

Plant height is one of the most important agronomic traits associated with yield in *** this study,a gibberellins(GA)-insensitive dwarf mutant,m34,was screened from inbred line Ye478 by treatment with the chemical mutagen ethylmethanesulfonate(EMS).Compared to Ye478,m34 showed a dwarf phenotype with shorter internodes,and smaller leaf length and width,but with similar leaf ***,m34 exhibited smaller guard cells in internodes than Ye478,suggesting that smaller cells might contribute to its dwarf *** analysis indicated that the m34 dwarf phenotype was controlled by a recessive nuclear *** F2 population derived from a cross between m34 and B73 was used for mutational gene cloning and this gene was mapped to a chromosome region between umc2189 and umc1553 in chromosome 1 bin1.10,which harbored a previously identified dwarf gene Zm *** analysis showed a nucleotide substitution(G1606 to A1606)in the sixth exon of ZmVP8,which resulted in an amino acid change(E531 to K531)from Ye478 to *** amino acid change resulted in anα-helix changing to aβ-sheet in the secondary protein structure and the‘SPEC’domain changed to a‘BOT1NT’domain in the tertiary protein *** together,these results suggested that m34 is a novel allelic mutant originally derived from Ye478 that is useful for further ZmVP8 functional analysis in maize.

关键词： dwarf plant height GA application ZmVP8 maize

How can leadership influence the quality ofcare in a health-care organization?

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Frontiers of Nursing 2020年第1期7卷 19-22页

作者： li-yuan xing Jing-Hui Song Fan Yan Department of Nursing Research Center Henan Provincial People’s HospitalPeople’s Hospital of Zhengzhou UniversityZhengzhouHenan 450003China Department of Dermatology Henan Provincial People’s HospitalPeople’s Hospital of Zhengzhou UniversityZhengzhouHenan 450003China

Objective:This study focuses on how leadership could influence the quality of care in a health-care ***:The concept of leadership and quality are *** addition,issues concerning how leadership can influence quality of care through the effect on the organizational culture and the engagement of both nurses and patients are ***:Leadership is the pivotal factor in the improvement of quality through the effect on the organizational culture and the engagement of both nurses and ***:Leadership can influence the quality of care directly and *** organization and the leaders should know the importance of effective leadership to a better work environment,facilitate the implementation of the new mode of nursing,and provide best services to the patients.

关键词： leadership quality of care organizational culture staff engagement patient engagement

Ammonium-dependent regulation of ammonium transporter ZmAMT1s expression conferred by glutamine levels in roots of maize

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Journal of Integrative Agriculture 2022年第8期21卷 2413-2421页

作者： HUI Jing liU Zhi DUAN Feng-ying ZHAO Yang li Xue-lian AN Xia WU Xiang-yu yuan li-xing College of Resources and Environmental Sciences China Agricultural UniversityBeijing 100193P.R.China

In maize,two root epidermis-expressed ammonium transporters ZmAMT1;1a and ZmAMT1;3 play major roles in highaffinity ammonium ***,the transcriptional regulation of ZmAMT1s in roots for ensuring optimal ammonium acquisition remains largely ***,using a split root system we showed that ZmAMT1;1a and ZmAMT1;3transcript levels were induced by localized ammonium supply to nitrogen-deficient *** enhanced expression of Zm AMT1s correlated with increases in ^(15)NH_(4)^(+)influx rates and tissue glutamine concentrations in *** ammonium was supplied together with methionine sulfoximine,an inhibitor of glutamine synthase,ammonium-induced expression of ZmAMT1s disappeared,suggesting that glutamine rather than ammonium itself regulated ZmAMT1s *** glutamine was supplied to nitrogen-deficient roots,expression levels of ZmAMT1s were enhanced,and negative feedback regulation could subsequently occur by supply of glutamine at a high ***,our results indicated an ammonium-dependent regulation of ZmAMT1s at transcript levels,and a dual role of glutamine was suggested in the regulation of ammonium uptake in maize roots.

关键词： ammonium transporter pH glutamine maize roots nitrogen transcriptional regulation

Transcriptional Regulation of Expression of the Maize Aldehyde Dehydrogenase 7 Gene (ZmALDH7B6) in Response to Abiotic Stresses

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Journal of Integrative Agriculture 2014年第9期13卷 1900-1908页

作者： AN Xia DUAN Feng-ying GUO Song CHEN Fan-jun yuan li-xing GU Ri-liang Department of Plant Nutrition Center for ResourcesEnvironment and Food SecurityChina Agricultural University

Aldehyde dehydrogenases（ALDHs） represent a large protein family, which includes several members that catalyze the oxidation of an aldehyde to its corresponding carboxylic acid in plants. Genes encoding members of the ALDH7 subfamily have been suggested to play important roles in various stress adaptations in plants. In this study, quantitative RT-PCR analysis revealed that a maize ALDH7 subfamily member（ZmALDH7B6） was constitutively expressed in various organs, including roots, leaves, immature ears, tassels, and developing seeds. The abundance of ZmALDH7B6 mRNA transcripts in maize roots was increased by ammonium, NaCl, and mannitol treatments. To further analyze tissue-specific and stress-induced expression patterns, the 1.5-kb 5′-flanking ZmALDH7B6 promoter region was fused to the β-glucuronidase（GUS） reporter gene and introduced into maize plants. In roots of independent transgenic lines, there was significant induction of GUS activity in response to ammonium supply, confirming ammonium-dependent expression of ZmALDH7B6 at the transcript level. Histochemical staining showed that GUS activity driven by the ZmALDH7B6 promoter was mainly localized in the vascular tissues of maize roots. These results suggested that ZmALDH7B6 is induced by multiple environmental stresses in maize roots, and may play a role in detoxifying aldehydes, particularly in vascular tissue.

关键词： abiotic stress aldehyde dehydrogenase gene expression promoter transgenic maize

Normal carcinoembryonic antigen indicates benefit from perioperative chemotherapy to gastric carcinoma patients

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World Journal of Gastroenterology 2012年第29期18卷 3910-3916页

作者： Shi Chen Ying-Bo Chen yuan-Fang li xing-Yu Feng Zhi-Wei Zhou Xiu-Hong yuan Chao-Nan Qian State Key Laboratory of Oncology in South China Sun Yat-sen Univer- sity Cancer Center Guangzhou 510060 Guangdong Province China

AIM:To evaluate pretreatment serum carcinoembryonic antigen(CEA) as a predictor of survival for patients with locally advanced gastric cancer receiving perioperative ***:We retrospectively studied a cohort of 228 gastric cancer patients who underwent D2 gastrectomy combined with chemotherapy at the Sun Yat-sen University Cancer Center between January 2005 and December *** them,168 patients received 6-12 cycles of oxaliplatin-based adjuvant(post-operative) chemotherapy,while 60 received perioperative chemotherapy(2 cycles of FOLFOX6 or XELOX before surgery and 4-10 cycles after surgery).Serum CEA was measured using an enzyme *** followup lasted until December ***:In the group that had elevated serum CEA,the difference in survival time between patients receiving perioperative chemotherapy and those receiving adjuvant chemotherapy had no statistical significance(P > 0.05).However,in the group that had normal serum CEA,patients receiving perioperative chemotherapy had a longer survival *** multivariate analysis,T staging and lymph node metastatic rate were independent prognostic factors for the *** chemotherapy improved the overall survival of patients who had a normal pretreatment CEA level(P = 0.070).CONCLUSION:Normal pretreatment serum CEA is a predictor of survival for patients receiving perioperative chemotherapy.

关键词： Carcinoembryonic antigen Perioperative chemotherapy Prognosis Gastric adenocarcinoma Survival

ON MULTICAST TREE CONSTRUCTION IN IPV4-IPV6 HYBRID NETWORK

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Journal of Electronics(China) 2010年第3期27卷 398-404页

作者： Zhang Chao Zhang yuan Huang Yongfeng li xing New Generation Network Lab Department of Electronic Engineering Tsinghua University Beijing 100084 China

With the IPv4 addresses exhausting and IPv6 emerging, the Peer-to-Peer (P2P) overlay is becoming increasingly heterogeneous and complex: pure IPv4, dual stack and pure IPv6 hosts coexist, and the connectivity limitation between IPv4 and IPv6 hosts requires the overlay protocols to be fit for this hybrid situation. This paper sets out to answer the question of how to construct multicast tree on top of IPv4-IPv6 hybrid network. Our solution is a New Greedy Algorithm (NGA) which eliminates the problem of joining failure in the hybrid network and keeps the efficiency of greedy algorithm in tree construction. Simulation results show that our algorithm has excellent performance, which is very close to the optimal in many cases.

关键词： IPv6 Peer-to-Peer (P2P) Multicast tree

Genetic Improvement of Root Growth Contributes to Efficient Phosphorus Acquisition in maize (Zea mays L.)

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Journal of Integrative Agriculture 2013年第6期12卷 1098-1111页

作者： ZHANG Yi-kai CHEN Fan-jun CHEN Xiao-chao LONG li-zhi GAO Kun yuan li-xing ZHANG Fu-suo MI Guo-hua Laboratory of Plant-Soil Interactions Ministry of Education/Center for Resources Environment and Food Security College of Resources and Environmental Science China Agricultural University

Maize plants adapt to low phosphorus （P） stress by increasing root growth. It is of importance to know the extent to which genetic improvement of root growth can enhance P acquisiton. In the present study, the contribution of root growth improvement to efficient P acquisition was evaluated in two soils using T149 and T222, a pair of near isogenic maize testcrosses which were derived from a backcross BC 4 F 3 population. T149 and T222 showed no difference in shoot biomass and leaf area under normal growth conditions, but differed greatly in root growth. T149 had longer lateral roots and a larger root surface area compared to T222. In calcareous soil, when P was insufficient, i.e., when P was either supplied as KH 2 PO 4 at a concentration of 50 mg P kg-1 soil, or in the form of Phy-P, Ca3-P or Ca10-P, a 43% increase in root length in T149 compared to T222 resulted in an increase in P uptake by 53%, and shoot biomass by 48%. In acid soil, however, when P supply was insufficient, i.e., when P was supplied as KH 2 PO 4 at a concentration of 100 mg P kg-1 soil, or in the form of Phy-P, Fe-P or Al-P, a 32% increase in root length in T149 compared to T222 resulted in an increase in P uptake by only 12%, and shoot biomass by 7%. No significant differences in the exudation of organic acids and APase activity were found between the two genotypes. It is concluded that genetic improvement of root growth can efficiently increase P acquisition in calcareous soils. In acid soils, however, improvements in the physiological traits of roots, in addition to their size, seem to be required for efficient P acquisition.

关键词： P efficiency roots low phosphorus calcareous soil acid soil maize

Local nitrogen application increases maize post-silking nitrogen uptake of responsive genotypes via enhanced deep root growth

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Journal of Integrative Agriculture 2023年第1期22卷 235-250页

作者： CHEN Zhe REN Wei YI Xia li Qiang CAI Hong-guang Farhan Ali yuan li-xing MI Guo-hua PAN Qing-chun CHEN Fan-jun College of Resources and Environmental Sciences/National Academy of Agriculture Green Development/Key Laboratory of Plant-Soil Interactions Ministry of EducationChina Agricultural UniversityBeijing 100193P.R.China Sanya Institute of China Agricultural University Sanya 572025P.R.China Institute of Agricultural Resource and Environment Jilin Academy of Agricultural SciencesChangchun 130033P.R.China Cereal Crops Research Institute Pirsabak Nowshera 24110Pakistan

Nitrogen(N)is unevenly distributed throughout the soil and plant roots proliferate in N-rich soil ***,the relationship between the root response to localized N supply and maize N uptake efficiency among different genotypes is *** this study,four maize varieties were evaluated to explore genotypic differences in the root response to local N application in relation to N uptake.A split-root system was established for hydroponically-grown plants and two methods of local N application(local banding and local dotting)were examined in the *** differences in the root length response to N were highly correlated between the hydroponic and field conditions(r>0.99).Genotypes showing high response to N,ZD958,XY335 and XF32D22,showed 50‒63%longer lateral root length and 36‒53%greater root biomass in N-rich regions under hydroponic conditions,while the LY13 genotype did not respond to *** field conditions,the root length of the high-response genotypes was found to increase by 66‒75%at 40‒60 cm soil depth,while LY13 showed smaller changes in root *** addition,local N application increased N uptake at the post-silking stage by 16‒88%in the high-response genotypes and increased the grain yield of ZD958 by 10‒12%.Moreover,yield was positively correlated with root length at 40‒60 cm soil depth(r=0.39).We conclude that local fertilization should be used for high-response genotypes,which can be rapidly identified at the seedling stage,and selection for“local-N responsive roots”can be a promising trait in maize breeding for high nitrogen uptake efficiency.

关键词： genotypic difference local nitrogen maize nitrogen efficient root