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The study of the supramolecular organization of the mitochondrial oxidative phosphorylation system (OXPHOS) in various eukaryotes has led to the accumulation of a considerable amount of data on the composition, stoichiometry, and architecture of its constituent superstructures. However, the link between the features of system arrangement and the biological characteristics of the studied organisms has been poorly explored. Here, we report a comparative investigation into supramolecular and functional OXPHOS organization in the mitochondria of etiolated shoots of winter wheat (Triticum aestivum L.), maize (Zea mays L.), and pea (Pisum sativum L.). Investigations based on BN-PAGE, in-gel activity assays, and densitometric analysis revealed both similarities and specific OXPHOS features apparently related to the life strategies of each species. Frost-resistant winter wheat was distinguished by highly stable basic I1III2IVa/b respirasomes and V2 dimers, highly active complex I, and labile complex IV, which were probably essential for effective OXPHOS adaptation during hypothermia. Maize, a C4 plant, had the highly stable dimers IV2 and V2, less active complex I, and active alternative NAD(P)H dehydrogenases. The latter fact could contribute to successful chloroplast–mitochondrial cooperation, which is essential for highly efficient photosynthesis in this species. The pea OXPHOS contained detergent-resistant high-molecular respirasomes I1–2III2IVn, highly active complexes IV and V, and stable succinate dehydrogenase, suggesting an active energy metabolism in organelles of this plant. The results and conclusions are in good agreement with the literature data on the respiratory activity of mitochondria from these species and are summarized in a proposed scheme of organization of OXPHOS fragments. [ABSTRACT FROM AUTHOR]

In recent years, worldwide scientific efforts towards controlling maize late wilt disease (LWD) have focused on eco-friendly approaches that minimize the environmental impact and health risks. This disease is considered to be the most severe threat to maize fields in Israel and Egypt, and a major growth restraint in India, Spain, and Portugal. Today's most commonly used method for LWD control involving resistant maize genotypes is under constant risk from aggressive pathogen lines. Thus, this study's objectives were to evaluate the effect of crop rotation and avoiding tillage on restraining the disease. Such an agrotechnical approach will support the continuity of soil mycorrhiza networks, which antagonize the disease's causal agent, Magnaporthiopsis maydis. The method gained positive results in previous studies, but many knowledge gaps still need to be addressed. To this end, a dual-season study was conducted using the LWD hyper-susceptible maize hybrid, Megaton cv. The trials were performed in a greenhouse and in the field over full dual-growth seasons (wheat or clover as the winter crop followed by maize as the summer crop). In the greenhouse under LWD stress, the results clearly demonstrate the beneficial effect of maize crop rotation with clover and wheat on plant weight (1.4-fold), height (1.1–1.2-fold) and cob yield (1.8–2.4-fold), especially in the no-till soil. The clover-maize growth sequence excels in reducing disease impact (1.7-fold) and pathogen spread in the host tissues (3-fold). Even though the wheat-maize crop cycle was less effective, it still had better results than the commercial mycorrhizal preparation treatment and the uncultivated non-infected soil. The results were slightly different in the field. The clover-maize rotation also achieved the best growth promotion and disease restraint results (2.6-fold increase in healthy plants), but the maize rotation with wheat showed only minor efficiency. Interestingly, pre-cultivating the soil with clover had better results in no-till soil in both experiments. In contrast, the same procedure with wheat had a better impact when tillage was applied. It may be concluded that crop rotation and soil cultivation can be essential in reducing LWD, but other factors may affect this approach's benefits in commercial field growth. [ABSTRACT FROM AUTHOR]

No-tillage of summer maize after the harvest of winter wheat is the main agricultural practice on the Huang-Huai-Hai (HHH) Plain of China. However, long-term no-tillage in the absence of deep tillage practices affects soil properties, and this effect is not beneficial for the growth and yield production of summer maize. Field experiments were conducted in 2016 in two agricultural sub-zones (Luancheng and Guoyang) in the HHH Plain. The main objective of this study was to evaluate the effect of deep vertical rotary tillage (DVRT), compared to no-tillage with strip subsoiling (NTSS), on dry matter accumulation (DMA) and yield formation. DVRT significantly reduced the soil bulk density of the top soil layer (0–40 cm), especially for the lime concretion black soil in the Guoyang experimental site. Compared with NTSS, the soil water content in the 20–60 cm soil layer was increased under the condition of DVRT. DVRT also significantly increased root DMA in the 0–30 cm soil layer in Luancheng and in the 0–40 cm soil layer in Guoyang. The total shoot DMA, seed DMA, and harvest index of DVRT were significantly higher than those of NTSS, primarily due to a significant increase in post-anthesis DMA. In addition, DVRT increased the maximum and mean grain filling rate and thus significantly increased the maximum grain weight at harvest. Compared with NTSS, DVRT significantly increased grain yield by 21.3% and 27.8% under the plant density of 6.75 pl m −2 and 9 pl m −2 , respectively, in Luancheng and it increased by 12.3% in Guoyang. The present results indicate that DVRT can be used as a deep tillage practice to improve soil properties and grain yield of summer maize, and this may provide guidance regarding the requirements to cope with a diversity of deep tillage machines and develop sustainable agriculture in the HHH Plain of China. [ABSTRACT FROM AUTHOR]

MiR396s play important roles in regulating plant growth and stress response, and great potential for crop yield promotion was anticipated. For more comprehensive and precise understanding of miR396s in Poaceae, we analyzed the phylogenetic linkage, gene expression, and chromosomal distribution of miR396s in this study. Although the mature miR396s' sequences were mostly conserved, differential expression patterns and chromosomal distribution were found among Poaceae species including the major cereal crops rice, wheat, and maize. Consistently, in comparison with rice, wheat and maize plants transformed with the target mimicry construct of miR396 (MIM396) exhibited differential effects on grain size and disease resistance. While the TaMIM396 plants showed increased grain size, panicle length and sensitivity to B. graminis , the ZmMIM396 plants didn't show obvious changes in grain size and disease resistance. In Addition, several GROWTH-REGULATING FACTOR (GRF) genes in wheat and maize were repressed by miR396s, which could be reversed by MIM396, confirming the conserved regulatory roles of miR396 on GRFs. While providing new solution to enhance grain yield in wheat and revealing potential regulatory variations of miR396s in controlling grain size and disease resistance in different crops, this study gives clues to further explore miR396s' functions in other Poaceae species. • Poaceae miR396s are divided into three groups and display both conserved and diversified evolutionary characterizations. • Inhibition of miR396s results in increased grain size, panicle length and pathogen sensitivity in wheat but not in maize. • Different GRFs were upregulated in the MIM396 transgenic plants compared to their corresponding wild type in wheat and maize. [ABSTRACT FROM AUTHOR]

Accumulation of greenhouse gases (GHGs) in the atmosphere has exposed us to the potential warming and its adverse effects on agriculture. The present study deals with the impact of climate change on winter wheat and maize using the Infocrop model. Simulation studies were performed for different timeperiods using HADCM3 factors at four centres located in three different agroecological zones, with prevalent management practices. The results showed that under changed climate, wheat yield decreased whereas the yield of winter maize increased due to warmer winters and enhanced CO2 compared to baseline. Duration of both the crops has decreased owing to the higher temperatures during the growing period. The increase in yield of winter maize points to the suitability of the region for its cultivation in future. Further, increase in maize cultivation in locations with poor wheat yield could well be considered as an adaptation option. [ABSTRACT FROM AUTHOR]

Abstract: Plant water status is a key factor impacting crop growth and agricultural water management. Crop water stress may alter canopy temperature, the energy balance, transpiration, photosynthesis, canopy water use efficiency, and crop yield. The objective of this study was to calculate the Crop Water Stress Index (CWSI) from canopy temperature and energy balance measurements and evaluate the utility of CWSI to quantify water stress by comparing CWSI to latent heat and carbon dioxide (CO2) flux measurements over canopies of winter wheat (Triticum aestivum L.) and summer maize (Zea mays L.). The experiment was conducted at the Yucheng Integrated Agricultural Experimental Station of the Chinese Academy of Sciences from 2003 to 2005. Latent heat and CO2 fluxes (by eddy covariance), canopy and air temperature, relative humidity, net radiation, wind speed, and soil heat flux were averaged at half-hour intervals. Leaf area index and crop height were measured every 7 days. CWSI was calculated from measured canopy-air temperature differences using the Jackson method. Under high net radiation conditions (greater than 500Wm−2), calculated values of minimum canopy-air temperature differences were similar to previously published empirically determined non-water-stressed baselines. Valid measures of CWSI were only obtained when canopy closure minimized the influence of viewed soil on infrared canopy temperature measurements (leaf area index was greater than 2.5m2 m−2). Wheat and maize latent heat flux and canopy CO2 flux generally decreased linearly with increases in CWSI when net radiation levels were greater than 300Wm−2. The responses of latent heat flux and CO2 flux to CWSI did not demonstrate a consistent relationship in wheat that would recommend it as a reliable water stress quantification tool. The responses of latent heat flux and CO2 flux to CWSI were more consistent in maize, suggesting that CWSI could be useful in identifying and quantifying water stress conditions when net radiation was greater than 300Wm−2. The results suggest that CWSI calculated by the Jackson method under varying solar radiation and wind speed conditions may be used for irrigation scheduling and agricultural water management of maize in irrigated agricultural regions, such as the North China Plain. [Copyright &y& Elsevier]

• We determined frequency of environment types (ENVT) for US maize, soybean, and wheat. • Each ENVT corresponded to a combination of drought and heat stress during critical period. • Inter-annual variation in drought and heat stress was higher than spatial variation. • The ENVT scheme explained observed variation in average actual yield for the three crops. • ENVTs can be used to link field-year experiments with target production environments. The impact of agricultural technologies on crop yield is influenced by the environment type (ENVT) as determined by weather and soil. Understanding the correlation between the ENVT of the testing site in relation to the ENVT of the target production region is important for the evaluation and scaling out of agricultural technologies. Here we propose and apply the first explicit method to characterize ENVTs for major rainfed maize, soybean, and wheat producing regions in the United States. We combined a tested spatial framework, Technology Extrapolation Domain (TED), with crop modeling, long-term (30-y) daily weather records, and soil and management databases to calculate the frequency of ENVTs per crop for major harvested areas. Each ENVT was determined based on the intensity of drought and heat stress during key crop stages for yield determination. The ENVT repeatability was calculated based on the frequency of the most dominant ENVT in each TED. We found that inter-annual variation in drought and heat stress was larger than spatial variation. Our ENVTs explained 2x to 7x larger portion of the variance in actual yield compared to the existing TED framework that is based on long-term annual climate means and soil water storage. For maize and soybean, ca. 30% of their harvested area was located in TEDs with highly repeatable ENVTs (>66% of years). In contrast, only 15% of the wheat harvested area was located in TEDs with high ENVT repeatability. In comparison to the TED framework, the ENVTs defined here can help better capture G×E×M interactions and determine the environmental correlation between testing sites and target production environments. [ABSTRACT FROM AUTHOR]

A double-cropping system such as that of winter wheat and summer maize in north China requires irrigation to achieve production goals. The soil during the seeding stage of summer maize is usually dry. For summer maize, soil moisture before sowing (SMBS) is important for seedling growth, yield, and water use. Our objective was to investigate the effects of applying different irrigation schedules to winter wheat on the SMBS, yield, and water use efficiency (WUE) of summer maize. Field experiments involving winter wheat with 0, 1, 2, and 3 irrigation applications (T0, T1, T2, and T3, respectively) were conducted in a dry year (2002), moderate year (2003), and humid year (2005). Irrigation of winter wheat increased the average SMBS of summer maize in the 1.2 m soil profiles to 17.7, 57.3, and 79.6 mm in T1, T2, and T3, respectively. Differences in the soil moisture content among the treatments were significant in the late growing season of summer maize in the dry and moderate years but not in the humid year. In 2005, maize yields among the treatments were not significantly different as compared to those in T0; the yields increased from 22.1% to 56.0% in 2002 and from 1.9% to 11.4% in 2003. Compared to T0, the WUE of summer maize increased by 15.3%, 23.6%, and 24. 7% in T1, T2, and T3, respectively, in 2002 and by 0.01%, 3.4%, and 5.4% in 2003; however, it decreased by 2.4%, 5.6%, and 12.4%, respectively, in 2005. Considering the combined WUE of winter wheat and summer maize, there was no significant difference between T2 and T3 (LSD, P < 0.05). These results suggest that winter wheat should be irrigated at the jointing and heading stages to achieve reasonable grain yield and WUE for both the crops. [ABSTRACT FROM AUTHOR]