Oxidation of self-stored carbohydrates and lipids provides the energy for the rapid morphogenetic transformation during asexual and infection-related development in Pyricularia oryzae, which results in intracellular accumulation of reducing equivalents NADH and FADH₂, requiring a cytosolic shuttling machinery towards mitochondria.  Our previous studies identified the mitochondrial D-lactate dehydrogenase MoDld1 as a regulator to channel the metabolite flow in conjunction with redox homeostasis.  However, the regulator(s) facilitating the cytosolic redox balance and the importance in propelling nutrient metabolite flow remain unknown.  The G-3-P shuttle is a conserved machinery transporting the cytosolic reducing power to mitochondria.  In P. oryzae, the mitochondrial G-3-P dehydrogenase Gpd2 was required for cellular NAD⁺/NADH balance and fungal virulence.  In this study, we re-locate the mitochondrial G-3-P dehydrogenase Gpd2 to the cytosol for disturbing cytosolic redox status.  Our results showed overexpression of cytosolic gpd2^Δmts without the mitochondrial targeted signal (MTS) driven by Ribosomal protein 27 promoter (PR27) exerted conflicting regulation of cellular oxidoreductase activities compared to the ΔModld1 deletion mutant by RNA-seq and prevented the conidiation and pathogenicity of P. oryzae.  Moreover, overexpression of gpd2^Δmts caused defects in glycogen and lipid mobilization underlying asexual and infectious structural development associated with decreased cellular NADH production and weakened anti-oxidation activities.  RNA-seq and non-targeted metabolic profiling revealed down-regulated transcriptional activities of carbohydrate metabolism and lower abundance of fatty acids and secondary metabolites in RP27:gpd2^Δmts.  Thus, our studies indicate the essential role of cytosolic redox control in nutrient metabolism fueling the asexual and infection-related development in P. oryzae.

The effect of nitrogen (N) fertilizer on the development of maize kernels has yet to be fully explored.  MicroRNA-mRNA analyses could help advance our understanding of how kernels respond to N.  This study analyzed the morphological, physiological, and transcriptomic changes in maize kernels under different N rates (0, 100, 200, and 300 kg ha^–1).  The result showed that increasing N application significantly increased maize grains’ fresh and dry weight until N reached 200 kg ha^–1.  Higher levels of indole-3-acetic acid, cytokinin, gibberellin, and a lower level of ethylene were associated with increased N applications.  We obtained 31 differentially expressed genes (DEGs) in hormone synthesis and transduction, and 9 DEGs were regulated by 14 differentially expressed microRNAs (DEMIs) in 26 pairs.  The candidate DEGs and DEMIs provide valuable insight for manipulating grain filling under different N rates.

Cold stress is an important factor that limits apple production.  In this study, we examined the tissue-cultured plantlets of apple rootstocks ‘M9T337’ and ‘60-160’, which are resistant and sensitive to cold stress, respectively.  The enriched pathways of differentially expressed genes (DEGs) and physiological changes in ‘M9T337’ and ‘60-160’ plantlets were clearly different after cold stress (1°C) treatment for 48 h, suggesting that they have differential responses to cold stress.  The differential expression of WRKY transcription factors in the two plantlets showed that MdWRKY40is and MdWRKY48 are potential regulators of cold tolerance.  When we overexpressed MdWRKY40is and MdWRKY48 in apple calli, the overexpression of MdWRKY48 had no significant effect on the callus, while MdWRKY40is overexpression promoted anthocyanin accumulation, increased callus cold tolerance, and promoted the expression of anthocyanin structural gene MdDFR and cold-signaling core gene MdCBF2.  Yeast one-hybrid screening and electrophoretic mobility shift assays showed that MdWRKY40is could only bind to the MdDFR promoter.  Yeast two-hybrid screening and bimolecular fluorescence complementation showed that MdWRKY40is interacts with the CBF2 inhibitor MdMYB15L through the leucine zipper (LZ).  When the LZ of MdWRMY40is was knocked out, MdWRKY40is overexpression in the callus did not affect MdCBF2 expression or callus cold tolerance, indicating that MdWRKY40is acts in the cold signaling pathway by interacting with MdMYB15L.  In summary, MdWRKY40is can directly bind to the MdDFR promoter in order to promote anthocyanin accumulation, and it can also interact with MdMYB15L to interfere with its inhibitory effect on MdCBF2, indirectly promoting MdCBF2 expression, and thereby improving cold tolerance.  These results provide a new perspective for the cold-resistance mechanism of apple rootstocks and a molecular basis for the screening of cold-resistant rootstocks.

The fully mulched ridge–furrow (FMRF) system has been widely used on the semi-arid Loess Plateau of China due to its high maize (Zea mays L.) productivity and rainfall use efficiency.  However, high outputs under this system led to a depletion of soil moisture and soil nutrients, which reduces its sustainability in the long run.  Therefore, it is necessary to optimize the system for the sustainable development of agriculture.  The development, yield-increasing mechanisms, negative impacts, optimization, and their relations in the FMRF system are reviewed in this paper.  We suggest using grain and forage maize varieties instead of regular maize; mulching plastic film in autumn or leaving the mulch after maize harvesting until the next spring, and then removing the old film and mulching new film; combining reduced/no-tillage with straw return; utilizing crop rotation or intercropping with winter canola (Brassica campestris L.), millet (Setaria italica), or oilseed flax (Linum usitatissimum L.); reducing nitrogen fertilizer and partially replacing chemical fertilizer with organic fertilizer; using biodegradable or weather-resistant film; and implementing mechanized production.  These integrations help to establish an environmentally friendly, high quality, and sustainable agricultural system, promote high-quality development of dryland farming, and create new opportunities for agricultural development in the semi-arid Loess Plateau.

Chinese cabbage is an economically important Brassica vegetable worldwide, and clubroot, which is caused by the soil-borne protist plant pathogen Plasmodiophora brassicae is regarded as a destructive disease to Brassica crops.  Previous studies on the gene transcripts related to Chinese cabbage resistance to clubroot mainly employed RNA-seq technology, although it cannot provide accurate transcript assembly and structural information.  In this study, PacBio RS II SMRT sequencing was used to generate full-length transcriptomes of mixed roots at 0, 2, 5, 8, 13, and 22 days after P. brassicae infection in the clubroot-resistant line DH40R.  Overall, 39 376 high-quality isoforms and 26 270 open reading frames (ORFs) were identified from the SMRT sequencing data.  Additionally, 426 annotated long noncoding RNAs (lncRNAs), 56 transcription factor (TF) families, 1 883 genes with poly(A) sites and 1 691 alternative splicing (AS) events were identified.  Furthermore, 1 201 of the genes had at least one AS event in DH40R.  A comparison with RNA-seq data revealed six differentially expressed AS genes (one for disease resistance and five for defensive response) that are potentially involved in P. brassicae resistance.  The results of this study provide valuable resources for basic research on clubroot resistance in Chinese cabbage.

The MADS-box (DAM) gene PpDAM6, which is related to dormancy, plays a key role in bud endodormancy release, and the expression of PpDAM6 decreases during endodormancy release.  However, the interaction network that governs its regulation of the endodormancy release of flower buds in peach remains unclear.  In this study, we used yeast two-hybrid (Y2H) assays to identify a mitogen-activated protein kinase, PpMAPK6, that interacts with PpDAM6 in a peach dormancy-associated SSHcDNA library.  PpMAPK6 is primarily located in the nucleus, and Y2H and bimolecular fluorescence complementation (BiFC) assays verified that PpMAPK6 interacts with PpDAM6 by binding to the MADS-box domain of PpDAM6.  Quantitative real-time PCR (qRT-PCR) analysis showed that the expression of PpMAPK6 was opposite that of PpDAM6 in the endodormancy release of three cultivars with different chilling requirements (Prunus persica ‘Chunjie’, Prunus persica var. nectarina ‘Zhongyou 5’, Prunus persica ‘Qingzhou peach’).  In addition, abscisic acid (ABA) inhibited the expression of PpMAPK6 and promoted the expression of PpDAM6 in flower buds.  The results indicated that PpMAPK6 might phosphorylate PpDAM6 to accelerate its degradation by interacting with PpDAM6.  The expression of PpMAPK6 increased with decreasing ABA content during endodormancy release in peach flower buds, which in turn decreased the expression of PpDAM6 and promoted endodormancy release.

This research aimed to improve selection of pepper seeds for separating high-quality seeds from low-quality seeds. Past research has shown that seed vigor is significantly related to the seed color and size, thus several physical features were identified as candidate predictors of high seed quality. Image recognition software was used to automate recognition of seed feature quality using 400 kernels of pepper cultivar 101. In addition, binary logistic regression and a neural network were applied to determine models with high predictive value of seed germination. Single-kernel germination tests were conducted to validate the predictive value of the identified features. The best predictors of seed vigor were determined by the highest correlation observed between the physical features and the subsequent fresh weight of seedlings that germinated from the 400 seeds. Correlation analysis showed that fresh weight was significantly positively correlated with eight physical features: three color features (R, a*, brightness), width, length, projected area, and single-kernel density, and weight. In contrast, fresh weight significantly negatively correlated with the feature of hue. In analyses of two of the highest correlating single features, germination percentage increased from 59.3 to 71.8% when a*≥3, and selection rate peaked at 57.8%. Germination percentage increased from 59.3 to 79.4%, and the selection rate reached 76.8%, when single-kernel weight ≥0.0064 g. The most effective model was based on a multilayer perceptron (MLP) neural network, consisting of 15 physical traits as variables, and a stability calculated as 99.4%. Germination percentage in a calibration set of seeds was 79.1% and the selection rate was 90.0%. These results indicated that the model was effective in predicting seed germination based on physical features and could be used as a guide for quality control in seed selection. Automated systems based on machine vision and model classifiers can contribute to reducing the costs and labor required in the selection of pepper seeds.

    Molybdenum (Mo) is an essential trace element in plant nutrition and physiology. It affects photosynthesis and photosynthate accumulation, therefore also affecting fruit quality and nutritional content. This study assessed the effects of different sodium molybdate (Na₂MoO₄) concentrations on strawberry. Five different Mo concentrations were applied in this experiment, including 0, 67.5, 135, 168.75, 202.5 g ha^–1, respectively. The mineral concentration, including nitrogen (N), Mo, iron (Fe), copper (Cu), and selenium (Se) was assessed in strawberry fruit, as well as chlorophyll content, nutrition quality, taste and aroma. Results showed that net photosynthetic rate (P_n) and chlorophyll content for the strawberry plants increased with an increase in Mo concentration; and the contents of N, Mo, Fe, Cu, total soluble solids (TSS), titratable acidity (TA), sweetness, some sugars, organic acids, and some volatile compounds in the fruit all increased, as well. However, the Mo concentration did not significantly affect the concentrations of Se, sucrose, lactic acid, acetic acid, and some aroma compounds. Fruit sprayed with 135 g ha^–1 Mo exhibited the highest TSS and sweetness values, as well as the highest N and Fe concentrations among all the treatments. Pn value and chlorophyll content, fructose, glucose, sorbitol and total sugar contents in fruit supplied with 135 g ha^–1 Mo were also higher than that in other treatments. Fruit sprayed with a Mo concentration of 67.5 g ha^–1 exhibited significantly higher ascorbic acid (AsA) values than that of control. Ninety-seven volatile compounds were identified in fruit extracted by head-space solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS). Fruits sprayed with 135 g ha^–1 Mo had the highest concentrations of six characteristic aroma compounds, including methyl butanoate, γ-decalactone, ethyl butanoate, methyl hexanoate, γ-dodecalactone, and ethyl caproate.

Keng stiffgrass is a grass weed that affects wheat-rice cropping systems in China.  The extensive reliance on acetyl coenzyme A carboxylase (ACCase)-inhibiting herbicides has resulted in keng stiffgrass developing resistance to these herbicides.  The objective of this research was to evaluate the resistance level of the putative resistant keng stiffgrass populations to ACCase-inhibiting herbicides and to identify their molecular resistance mechanism.  Whole-plant dose-response experiments demonstrated that SD-4 (R), SD-11 (R), and JS-25 (R) populations were highly resistant to fenoxaprop, clodinafop, and fluazifop, moderately resistant to diclofop, had low resistance to sethoxydim and pinoxaden, but were sensitive to clethodim.  Partial chloroplastic ACCase sequences showed that there were two copies of ACCase gene in keng stiffgrass, and all homoeologous genes were expressed.  The results of sequence analyses of the ACCase CT domain revealed an isoleucine-to-asparagine substitution at position 2041 in SD-4 (R) and SD-11 (R) populations, and a tryptophan-to-cysteine substitution at position 2027 in the JS-25 (R) population.  To our knowledge, this is the first report of Ile-2041-Asn and Trp-2027-Cys mutations in ACCase-resistant keng stiffgrass.  In addition, three robust (derived) cleaved amplified polymorphic sequence ((d)CAPS) markers have been developed to rapidly identify these mutations in the ACCase gene of keng stiffgrass.

    Information on the center of genetic diversity of soybean (Glycine max) will be helpful not only for designing efficient strategies for breeding programs, but also for understanding the domestication and origin of this species. Here, we describe an analysis of genetic diversity based on simple-sequence repeat (SSR) variations within a core collection of 2 111 accessions of Chinese soybean landraces. Prior to the diversity assessment, the geographic origin of each accession was mapped. The map was then divided into grids each 2.5° in latitude and 5° in longitude. We found two regions that had higher number of alleles (NA) and greater polymorphic information content (PIC) values than the others. These regions are adjacently located within grid position of 30°–35°N×105°–110°E, which includes the valley of the middle and lower reaches of the Wei River, and the valley of the upper reaches of the Hanjiang River. It was also observed that in many regions, genetic diversity decreased with the increase in distance from the center. Another region, in northern Hebei Province (115°–120°E×40°–42.5°N), was observed having higher diversity than any surrounding regions, indicating that this is a sub-center of soybean diversity. Based on the presented results, the domestication and origin of soybean are also discussed.

Laboratory aerobic incubation was conducted for 161 d to study N mineralization and the changes of organic N fractions of nine different manures (3 chicken manures, 3 pig manures and 3 cattle manures) from different farms/locations. Results indicated that significant (P<0.01 or P<0.001) difference existed in N mineralization between manures. The rapid N mineralization in manures occurred during 56 to 84 d of incubation. First order exponential model can be used to describe N mineralization from chicken manures and pig manures, while quadratic equation can predict mineralization of organic N from cattle manures. An average of 21, 19 and 13% added organic N from chicken manure, pig manure and cattle manure was mineralized during 161 d of incubation. Amino acid-N was the main source of N mineralization. The changes of amino acid-N together with ammonium N could explain significantly 97 and 96% of the variation in mineralized N from manured soils and manures. Amino acid-N and ammonium N are two main N fractions in determining N mineralization potential from manures. Amino acid-N contributed more to the mineralized N than ammonium N.

Although water and energy resources are well-recognized concerns regarding economic and social development sustainability, little specific research has focused on both water and energy problems at the same time. This study analyzed the water and electricity-use patterns in Shenzhen, South China during 2001-2009. A curve regression method was used to examine the relationship between water and electricity use per gross domestic product (GDP) in Shenzhen and its three sectors, i.e., agriculture, industry & construction, and residential life & services. Results showed that agriculture only covered less than 10% of water and electricity use in Shenzhen, while industry & construction and residential life & services accounted for more than 90% of water and electricity use in Shenzhen, which coincided with the city’s industrial structure. The water and electricity use per GDP in agriculture was the biggest among three sectors in Shenzhen during 2001-2009, which means inefficiency of water and electricity use in agriculture. Due to transitioning to advanced materials and manufacturing, both water and electricity use per GDP in industry & construction decreased during 2001-2009 and their utilization efficiencies gradually increased over time. The same held true for those in residential life & services transformed toward modern business, creative culture, finance services, etc. Derived from the survival of the fittest in competing for limited water and electricity resources, agriculture in Shenzhen has been gradually substituted by industry & construction and residential life & services, with much higher efficiencies of water and electricity use. And traditional agriculture will not be sustainable in the process of urbanization and industrialization, except high-tech intensive agriculture with low water and energy cost. Furthermore, by means of curve regression, we found that there was a significant quadratic relationship between water use per GDP and electricity use per GDP in the entire city and its three sectors. Suitable industrial transformation and advancement was a very effective way to save water and energy for modern cities. This can provide some reference for systematic planning and design of water and electricity allocation and use in agriculture, industry & construction and residential life & services in a city.

High temperature stress (HT) is efficient in breaking endo-dormancy of perennial trees. The effects of HT (50°C) on the respiration of dormant nectarine (Prunus persica var. nectariana cv. Shuguang) vegetative buds were evaluated in the research. We found that bud respiration was transiently inhibited by HT and the pentose phosphate pathway (PPP) and the cytochrome C pathway (CYT) were significantly affected. On the substrate level, PPP was activated in the HT-treated buds compared with the control group. However, the activation did mot occur until hours after HT treatment. The tricarboxylic acid cycle (TCA) in both the HT-treated buds and in the control group proceeded at a low level most of the time compared with total respiration. On the electron transfer level, CYT was transiently inhibited by HT but became significantly active in the later stage. CYT operation in the control group exhibited an attenuation process. The alternative pathway (ALT) fluctuated both in the HT-treated samples and in the control. The results suggest that the temporary CYT inhibition and the following PPP activation may be involved in HT-induced bud dormancy release and budburst mechanisms.

Shuguang (Prunus persica var. nectariana cv. Shuguang) nectarine was used to study effects of photoperiod on keyenzymeactivities of respiration during dormancy induction. The dormancy status was determined with sprouting ability.Spectrophotometry was used to investigate activities of phosphohexose isomerase (PGI), malic dehydrogenase (MDH),and glucose-6-phosphate dehydrogenase (G6PDH). The results revealed that short day (SD) treatment promoted dormancyinduction while long day (LD) treatment postponed the process. During dormancy induction, PGI activities declined,MDH activities changed little, and G6PDH activities increased both in flower buds and leaf buds. PGI activities and MDHactivities in SD treatment were lower than control, and G6PDH activities were higher, which was opposite with LDtreatment. The changes of respiratory key-enzyme activities were adjusted by photoperiod and correlated with thedevelopment of dormancy induction.

Conservation agriculture has been practised for three decades and has been spread widely. There are many nomenclatures surrounding conservation agriculture and differ to each other lightly. Conservation agriculture (CA) is a system approach to soil and water conservation, high crop productivity and profitability, in one word, it is a system approach to sustainable agriculture. Yet, because conservation agriculture is a knowledge-intensive and a complex system to learn and implement, and also because of traditions of intensive cultivation, adoption rates have been low, since to date, only about seven percent of the world’s arable and permanent cropland area is farmed under conservation agriculture. The practice and wider extention of conservation agriculture thus requires a deeper understanding of its ecological underpinnings in order to manage its various elements for sustainable intensification, where the aim is to conserve soil and water and improve sustainability over the long term. This paper described terms related to conservation agriculture, presented the effects of conservation agriculture on soil and water conservation, crop productivity, progress and adoption of CA worldwide, emphasized obstacles and possible ways to increase CA adoption to accelerate sustainable development of China agriculture.

Characteristics of dormancy induction and alternative respiration pathway (also known as cyanide-resistant respiration) of nectarine flower buds in different photoperiods were studied to determine the function of photoperiod and alternative respiration pathway in dormancy induction. Oxygen-electrode system and respiratory inhibitors were used to measure total respiratory rates and rates of alternative respiration pathway. The results showed that total respiration rate (Vt) in flower buds showed to be double hump-shaped curves. Short day raised, brought the first-hump of Vt forward and delayed the second-hump, while long day delayed the whole curve. The capacity (Valt) and activity (ρValt) of SD and LD changed synchronously and both showed to be double hump-shaped curves. Short day made the first climax of Valt and ρValt existed much earlier, while long day increased their rates significantly. The length of day had little effects on the later period climax. Long day also increased the contributions of alternative respiration pathway in total respiration rate (ρValt/Vt). The changes in alternative respiration pathway were correlated with the induction of dormancy and adjusted by photoperiod. Short day promoted dormancy induction of nectarine trees, while long day delayed it.