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1.
BMC Plant Biol ; 20(1): 44, 2020 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-31996151

RESUMO

BACKGROUND: Exogenous 6-benzyladenine (6-BA) could improve leaf defense system activity. In order to better understand the regulation mechanism of exogenous 6-benzyladenine (6-BA) on waterlogged summer maize, three treatments including control (CK), waterlogging at the third leaf stage for 6 days (V3-6), and application of 100 mg dm- 3 6-BA after waterlogging for 6 days (V3-6-B), were employed using summer maize hybrid DengHai 605 (DH605) as the experimental material. We used a labeling liquid chromatography-based quantitative proteomics approach with tandem mass tags to determine the changes in leaf protein abundance level at the tasseling stage. RESULTS: Waterlogging significantly hindered plant growth and decreased the activities of SOD, POD and CAT. In addition, the activity of LOX was significantly increased after waterlogging. As a result, the content of MDA and H2O2 was significantly increased which incurred serious damages on cell membrane and cellular metabolism of summer maize. And, the leaf emergence rate, plant height and grain yield were significantly decreased by waterlogging. However, application of 6-BA effectively mitigated these adverse effects induced by waterlogging. Compared with V3-6, SOD, POD and CAT activity of V3-6-B were increased by 6.9, 12.4, and 18.5%, LOX were decreased by 13.6%. As a consequence, the contents of MDA and H2O2 in V3-6-B were decreased by 22.1 and 17.2%, respectively, compared to that of V3-6. In addition, the leaf emergence rate, plant height and grain yield were significantly increased by application of 6-BA. Based on proteomics profiling, the proteins involved in protein metabolism, ROS scavenging and fatty acid metabolism were significantly regulated by 6-BA, which suggested that application of 6-BA exaggerated the defensive response of summer maize at proteomic level. CONCLUSIONS: These results demonstrated that 6-BA had contrastive effects on waterlogged summer maize. By regulating key proteins related to ROS scavenging and fatty acid metabolism, 6-BA effectively increased the defense system activity of waterlogged summer maize, then balanced the protein metabolism and improved the plant physiological traits and grain yield.

2.
Ying Yong Sheng Tai Xue Bao ; 30(11): 3771-3776, 2019 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-31833690

RESUMO

Suitable nitrogen application rate can significantly increase grain filling rate and yield and improve nutritional quality. Denghai 518 (DH518) and Zhengdan 958 (ZD958) were used as experimental materials in this study. A field experiment with four treatments, no nitrogen treatment (N0), decrement nitrogen application rate (N1, 129 kg N·hm-2), suitable nitrogen rate (N2, 184.5 kg N·hm-2) and excessive nitrogen rate (N3, 300 kg N·hm-2), was conducted to explore the effects of nitrogen fertilization on grain filling parameters and nutritional qualities of summer maize. Results showed that grain filling characteristics, grain dry weight, and yield in N0 treatment was decreased. With increasing nitrogen application rate in the suitable range, average filling rate, grain dry weight, and yield increased. Grain yield of two hybrids in N1 and N2 treatments was higher than that of N0 by 16.4%-57.2% and 35.8%-65.1%, respectively. Grain protein, soluble sugar, starch contents and the ratio of amylopectin and amylase contents were lower and crude fat content was higher in N0 treatment. Grain protein content, soluble sugar content and starch content in N2 of DH518 were higher than that of N0 and N1 by 32.5% and 6.5%, 19.9% and 9.5%, 8.9% and 5.2%, and the ratio of amylopectin and amylose contents was increased. Grain protein, soluble sugar and starch contents in N2 of ZD958 were higher than that of N0 and N1 by 16.9% and 7.8%, 30.5% and 14.8%, 11.5% and 5.7%, and the ratio of amylopectin and amylase contents was increased. Crude fat content in N2 of both hybrids decreased significantly by 4.8%-12.3% than that of N0 and N1. However, yield and nutritional quality was increased in N3 treatment than that of N2. Our results suggested that suitable nitrogen rate could enhance grain filling, grain weight, and grain nutritional quality.


Assuntos
Nitrogênio , Zea mays , Grão Comestível , Fertilizantes , Valor Nutritivo , Estações do Ano
3.
Sci Total Environ ; 687: 1138-1146, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31412450

RESUMO

The North China Plain (NCP) is typically cropped using a winter wheat-summer maize double cropping system, which has huge potential for straw production. The region also experiences atmospheric pollution caused by straw burning, which has become an important contributor to global warming. The goals of this experiment were to resolve the conflict between soil fertility and greenhouse gas emission when using straw return to the field and to identify the best balance between environmental protection and agricultural production. A randomized block design with three replicates was used. The design included three treatments based on the return of all winter wheat stalks to the field: (1) all summer maize stalks were pulverized mechanically and returned to the field (SR); (2) half of the summer maize stalks were pulverized mechanically and returned to the field (1/2 SR); and (3) all summer maize stalks were fully removed (control: CK). This long-term test was performed for 6 years. Straw returned to the field significantly increased greenhouse gas emissions. The cumulative CO2 emissions were higher by 32% under SR and by 17% under 1/2 SR compared with CK. The cumulative N2O emissions were higher by 28% under SR and 15% under 1/2 SR compared with CK. The greenhouse gas efflux increased with increased amounts of straw returned to the field. Compared with SR, 1/2 SR significantly reduced greenhouse gas emissions, while still ensuring sustainable soil fertility. Additionally, our research showed that the upper part of the corn stalk is better for generating biomass energy than the lower part. This study provides a theoretical basis for using the upper stalk for bioenergy and the lower stalk for direct return to the field for fertilization.


Assuntos
Agricultura , Gases de Efeito Estufa/análise , Triticum , Zea mays , China , Aquecimento Global , Estações do Ano , Solo/química
4.
Front Plant Sci ; 8: 1821, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29123536

RESUMO

Maize is one of the most important crops globally that provides food, feed, and bioenergy. However, shading stress threatens maize production. In this study, we investigated the effects of shading on photosynthate accumulation and distribution of summer maize in the field. Zhengdan958 (ZD958) and Denghai 605 (DH605) were used as experimental materials in a field experiment running from 2013 to 2015. Shading treatments were applied over different growth stages: from the tassel stage (VT) to physiological maturity (R6) (S1), from the six-leaf stage (V6) to VT (S2), and from emergence stage (VE) to R6 (S3). The effects of shading on plant photosynthesis, photosynthate accumulation and distribution, and yield were evaluated in comparison to ambient sunlight. Shading significantly decreased the leaf area, SPAD value, net photosynthetic rate, dry matter accumulation, and grain yield. During the 3-year experimental period, grain yields of ZD958 and DH605 were reduced by 83.4%, 34.2%, 53.1% and 79.3%, 24.2%, 57.6% as compared to the CK by treatments S3, S2, and S1, respectively. 13CO2 stable isotope tracing revealed that shading differentially affected the photosynthate transfer rate in different stages; photosynthates were transferred from top to bottom plant parts, in the order control > S2 > S1 > S3. We conclude that shading clearly disrupted photosynthate metabolism, and reduced the photosynthate accumulation in the grain, resulting in a yield reduction.

5.
Front Plant Sci ; 8: 1216, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28744299

RESUMO

We performed a field experiment using the maize hybrids DengHai605 (DH605) and ZhengDan958 (ZD958) to study nitrogen uptake and translocation, key enzyme activities of nitrogen metabolism in response to waterlogging at the third leaf stage (V3), the sixth leaf stage (V6), and the 10th day after the tasseling stage (10VT). Results showed that N accumulation amount was significantly reduced after waterlogging, most greatly in the V3 waterlogging treatment (V3-W), with decreases of 41 and 37% in DH605 and ZD958, respectively. N accumulation in each organ and N allocation proportions in grains decreased significantly after waterlogging, whereas N allocation proportions increased in stem and leaf. The reduction in stem and leaf N accumulation after waterlogging was mainly caused by a decrease in dry matter accumulation, and a reduction in N translocation from stems and leaves to grains after waterlogging. Additionally, waterlogging decreased the activity of key N metabolism enzymes (nitrate reductase, glutamine, glutamate synthase, and glutamate dehydrogenase), and the most significant reduction in V3-W with a decrease of 59, 46, 35, and 26% for DH605, and 60, 53, 31, and 25 for ZD958, respectively. Waterlogging disrupted N metabolism, hindered N absorption and transportation, and decreased maize yield.

6.
Naturwissenschaften ; 104(3-4): 12, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28246890

RESUMO

Plant density has been recognized as a major factor determining the grain yield. The photosynthetic performance changes as the density increases. The main objective of this research was to evaluate responses of photosynthetic performance and chloroplast ultrastructure to planting densities in two summer maize (Zea mays L.) hybrids Denghai661 (DH661) and Nongda108 (ND108). DH661 was planted at densities of 30,000, 45,000, 60,000, 75,000, 90,000, 105,000, 120,000, or 135,000 plants ha-1. ND108 was planted at densities of 30,000, 45,000, 60,000, 75,000, or 90,000 plants ha-1. Research variables included leaf area, grain yield, chlorophyll content, leaf gas exchange parameters, number of chloroplasts, and chloroplast ultrastructure. As plant density increased, chlorophyll a and b content significantly decreased; carotenoids initially decreased and then increased; the net photosynthetic rate during each growth period significantly decreased; the membrane structure of mesophyll cells was gradually damaged; the number of chloroplasts significantly decreased; the external form of chloroplasts shifted from long and oval to elliptical or circular; the number of grana significantly decreased, while the number of grana lamellae increased; grana gradually became hypogenetic and eventually dissolved; plot yield increased; and yield per plant significantly decreased. The yield per plant of DH661 at 135,000 plants ha-1 and that of ND108 at 90,000 plants ha-1 decreased by 65.8 and 42.5%, respectively, compared with those at 30,000 plants ha-1.


Assuntos
Cloroplastos/ultraestrutura , Fotossíntese/fisiologia , Zea mays/fisiologia , Zea mays/ultraestrutura , Clorofila/análise , Cloroplastos/química , Folhas de Planta/anatomia & histologia , Densidade Demográfica , Estações do Ano , Sementes/anatomia & histologia , Zea mays/anatomia & histologia
7.
PLoS One ; 11(9): e0161424, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27583803

RESUMO

A field experiment was performed to study the effects of waterlogging on the leaf mesophyll cell ultrastructure, chlorophyll content, gas exchange parameters, chlorophyll fluorescence, and malondialdehyde (MDA) content of summer maize (Zea mays L.) hybrids Denghai605 (DH605) and Zhengdan958 (ZD958). The waterlogging treatments were implemented for different durations (3 and 6 days) at the third leaf stage (V3), the sixth leaf stage (V6), and the 10th day after the tasseling stage (10VT). Leaf area index (LAI), chlorophyll content, photosynthetic rate (Pn), and actual photochemical efficiency (ΦPSII) were reduced after waterlogging, indicating that waterlogging significantly decreased photosynthetic capacity. The chloroplast shapes changed from long and oval to elliptical or circular after waterlogging. In addition, the internal structures of chloroplasts were degenerated after waterlogging. After waterlogging for 6 d at V3, the number of grana and grana lamellae of the third expanded leaf in DH605 were decreased by 26.83% and 55.95%, respectively, compared to the control (CK). Those in ZD958 were reduced by 30.08% and 31.94%, respectively. Waterlogging increased MDA content in both hybrids, suggesting an impact of waterlogging on membrane integrity and thus membrane deterioration. Waterlogging also damaged the biological membrane structure and mitochondria. Our results indicated that the physiological reactions to waterlogging were closely related to lower LAI, chlorophyll content, and Pn and to the destruction of chloroplast ultrastructure. These negative effects resulted in the decrease of grain yield in response to waterlogging. Summer maize was the most susceptible to damage when waterlogging occurred at V3, followed by V6 and 10VT, with damage increasing in the wake of waterlogging duration increasing.


Assuntos
Células do Mesofilo/ultraestrutura , Fotossíntese , Folhas de Planta/ultraestrutura , Estações do Ano , Água , Zea mays/fisiologia , Clorofila/metabolismo , Malondialdeído/metabolismo , Células do Mesofilo/metabolismo , Microscopia Eletrônica de Transmissão , Folhas de Planta/metabolismo , Espectrometria de Fluorescência , Zea mays/citologia , Zea mays/metabolismo
8.
Naturwissenschaften ; 103(7-8): 67, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27437706

RESUMO

A field experiment was conducted to study the effects of shading on the photosynthetic characteristics and mesophyll cell ultrastructure of two summer maize hybrids Denghai605 (DH605) and Zhengdan958 (ZD958). The ambient sunlight treatment was used as control (CK) and shading treatments (40 % of ambient sunlight) were applied at different growth stages from silking (R1) to physiological maturity (R6) (S1), from the sixth leaf stage (V6) to R1 (S2), and from seeding to R6 (S3), respectively. The net photosynthetic rate (P n) was significantly decreased after shading. The greatest reduction of P n was found at S3 treatment, followed by S1 and S2 treatments. P n of S3 was decreased by 59 and 48 % for DH605, and 39 and 43 % for ZD958 at tasseling and milk-ripe stages, respectively, compared to that of CK. Additionally, leaf area index (LAI) and chlorophyll content decreased after shading. In terms of mesophyll cell ultrastructure, chloroplast configuration of mesophyll cells dispersed, and part of chloroplast swelled and became circular. Meanwhile, the major characteristics of chloroplasts showed poorly developed thylakoid structure at the early growth stage, blurry lamellar structure, loose grana, and a large gap between slices and warping granum. Then, plasmolysis occurred in mesophyll cells and the endomembrane system was destroyed, which resulted in the dissolution of cell membrane, karyotheca, mitochondria, and some membrane structures. The damaged mesophyll cell ultrastructure led to the decrease of photosynthetic capacity, and thus resulted in significant yield reduction by 45, 11, and 84 % in S1, S2, and S3 treatments, respectively, compared to that of CK.


Assuntos
Células do Mesofilo/ultraestrutura , Fotossíntese/fisiologia , Luz Solar , Zea mays/fisiologia , Zea mays/efeitos da radiação , Cloroplastos/efeitos da radiação , Cloroplastos/ultraestrutura , Células do Mesofilo/efeitos da radiação , Fotossíntese/efeitos da radiação , Folhas de Planta/citologia , Folhas de Planta/fisiologia , Folhas de Planta/efeitos da radiação , Folhas de Planta/ultraestrutura , Zea mays/citologia , Zea mays/ultraestrutura
9.
Ying Yong Sheng Tai Xue Bao ; 26(5): 1397-403, 2015 May.
Artigo em Chinês | MEDLINE | ID: mdl-26571657

RESUMO

This study explored the effects of different tillage treatments at pre-planting winter wheat and summer maize on leaf senescence physiological characteristics of summer maize in double cropping system. Zhengdan 958 was used as experimental material. Three tillage treatments, including rotary tillage before winter wheat seeding and no-tillage before summer maize seeding (RN), mold- board plow before winter wheat seeding and no-tillage before summer maize seeding (MN), and moldboard plow before winter wheat seeding and rotary tillage before summer maize seeding (MR), were designed to determine the effects of different tillage treatments on leaf area (LA) , leaf area reduction, photosynthetic pigments content, superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) activities and malondialdehyde (MDA) content in ear leaves of summer maize after tasselling (VT). LA of MN and MR were higher than that of RN from VT to 40 days after tasseling (VT + 40) and LA reduction of MR was the highest after VT + 40. As for MR, MN and NT, the photosynthetic pigments content got the maximum value at 20 days after tasselling (VT + 20) and then decreased, following the change of unimodal curve. At VT + 20, the contents of chlorophyll a in MR and MN were increased by 11.4% and 9.7%, the contents of chlorophyll b in MR and MN were increased by 14.9% and 15.9%, compared with RN. The soluble protein content in ear leaves decreased following the growth process in all treatments, and that of MR and MN remained 11.5% and 24.4% higher than that of RN from VT to VT + 40. SOD, CAT and POD activities of three treatments got the maximum values at VT + 20 and then decreased, following the change of unimodal curve. MDA content increased following the growth process in all treatments and that of RN always remained at high levels. Grain yields of MN and MR were 24.0% and 30.6% greater than that of RN, respectively. Grain yield of MR was 5.2% higher than that of MN. In conclusion, the ability of leaf senescence resistance of MN was improved, which was helpful to increase the yield of summer maize.


Assuntos
Agricultura/métodos , Folhas de Planta/fisiologia , Triticum/crescimento & desenvolvimento , Zea mays/fisiologia , Catalase/metabolismo , Clorofila/análise , Malondialdeído , Peroxidases/metabolismo , Fotossíntese , Superóxido Dismutase/metabolismo
10.
Ying Yong Sheng Tai Xue Bao ; 25(4): 1022-8, 2014 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-25011294

RESUMO

Taking two summer maize hybrids Zhengdan 958 (ZD958) and Denghai 605 (DH605) as experimental materials, a field experiment was conducted to explore the effects of waterlogging for different durations (3 and 6 days) on leaf senescence characteristics of summer maize at the three-leaf stage (V3), six-leaf stage (V6), and 10 days after the tasseling stage (10VT). Results showed that superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) activities and soluble protein content decreased significantly after waterlogging. However, the content of malondialdehyde (MDA) increased significantly by 35.3% and 34.1% for DH605 and ZD958, respectively. The leaf chlorophyll content and grain yield of summer maize decreased significantly after waterlogging. The grain yields of DH605 and ZD958 after waterlogging for 6 days at V3 were most seriously affected, which were decreased by 32.1% and 35.2%, respectively. Overall, the summer maize was most susceptible to the effect of waterlogging at V3, followed by V6 and 10VT, and the influence extent increased with the increase of waterlogging duration.


Assuntos
Inundações , Folhas de Planta/fisiologia , Água , Zea mays/fisiologia , Catalase/química , Malondialdeído/química , Peroxidase/química , Proteínas de Plantas/química , Estações do Ano , Superóxido Dismutase/química
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