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Nitrogen (N) and carbon (C) are essential elements for plant growth and crop yield. Thus, improved N and C utilisation contributes to agricultural productivity and reduces the need for fertilisation. In the present study, we find that overexpression of a single rice gene, Oryza sativa plasma membrane (PM) H + -ATPase 1 ( OSA1 ), facilitates ammonium absorption and assimilation in roots and enhanced light-induced stomatal opening with higher photosynthesis rate in leaves. As a result, OSA1 overexpression in rice plants causes a 33% increase in grain yield and a 46% increase in N use efficiency overall. As PM H + -ATPase is highly conserved in plants, these findings indicate that the manipulation of PM H + -ATPase could cooperatively improve N and C utilisation, potentially providing a vital tool for food security and sustainable agriculture. Improved utilisation of nitrogen and carbon could boost agricultural productivity. Here Zhang et al. show that overexpression of a single gene, encoding the plasma membrane H +  -ATPase 1 OSA1, is able to increase both carbon fixation via photosynthesis and nitrogen assimilation via ammonium uptake in rice.

Biological nitrification inhibitors (BNIs) are released from plant roots as exudates to repress nitrifier activity in agricultural soils, and this can improve nitrogen (N) recovery from fertilizer and enhance the N-use-efficiency (NUE). This review summarizes the current understanding of the regulatory mechanisms of BNIs release from roots of plants, such as Brachiaria humidicola (pasture grasses), Sorghum bicolor (hybrid sorghum) and Oryza sativa (paddy rice). BNIs can be categorized as hydrophilic- and hydrophobic-BNIs. Root systems can rapidly release hydrophilic-BNIs when NH4+ is present in rhizosphere in combination with low pH, which is associated with the activation of plasma membrane H+-ATPase. Since plasma membrane H+-ATPase is responsible for the establishment of membrane potential and generation of proton motive force for the secondary transport of various substances. The BNIs release may probably occur through the voltage-gated anion channels by the membrane potential variation or via secondary transporters, most likely MATE transporters, powered by the proton motive force. In addition, ATP-binding cassette (ABC) transporters may be also involved in the active efflux of hydrophilic-BNIs. On the contrary, the release of the hydrophobic BNIs, such as sorgoleone, from plant roots may be mediated by the vesicle traffic process and/or exocytosis. In addition, the possible effects of various environmental factors on the BNIs release in soils have been discussed. Future research should focus on the identification of the corresponding BNIs transporters in plants, and this may be helpful for the application of BNI crops in the agricultural practice via breeding and genetic modification.

Plasma membrane (PM) H+-ATPase is a master enzyme involved in various plant physiological processes, such as stomatal movements in leaves and nutrient uptake and transport in roots. Overexpression of Oryza sativa PM H+-ATPase 1 (OSA1) has been known to increase NH4+ uptake in rice roots. Although electrophysiological and pharmacological experiments have shown that the transport of many substances is dependent on the proton motive force provided by PM H+-ATPase, the exact role of PM H+-ATPase on the uptake of nutrients in plant roots, especially for the primary macronutrients N, P, and K, is still largely unknown. Here, we used OSA1 overexpression lines (OSA1-oxs) and gene-knockout osa1 mutants to investigate the effect of modulation of PM H+-ATPase on the absorption of N, P, and K nutrients through the use of a nutrient-exhaustive method and noninvasive microtest technology (NMT) in rice roots. Our results showed that under different concentrations of P and K, the uptake rates of P and K were enhanced in OSA1-oxs; by contrast, the uptake rates of P and K were significantly reduced in roots of osa1 mutants when compared with wild-type. In addition, the net influx rates of NH4+ and K+, as well as the efflux rate of H+, were enhanced in OSA1-oxs and suppressed in osa1 mutants under low concentration conditions. In summary, this study indicated that overexpression of OSA1 stimulated the uptake rate of N, P, and K and promoted flux rates of cations (i.e., H+, NH4+, and K+) in rice roots. These results may provide a novel insight into improving the coordinated utilization of macronutrients in crop plants.

Banana production has been severely hindered by the long-term practice of monoculture agriculture. Fusarium wilt, caused by the Fusarium oxysporum f. sp. cubense (FOC), is one of the most destructive diseases that can afflict banana plants. It is both necessary and urgent to find an efficient method for protecting banana production worldwide. In this study, 57 antagonistic bacterial strains were isolated from the rhizospheres of healthy banana plants grown in a heavily wilt-diseased field; of the 57 strains, six strains with the best survival abilities were chosen for further study. Compared with the control and the other strains in the greenhouse experiment, W19 strain was found to observably decrease the incidence of Fusarium wilt and promote the growth of banana plants when combined with the organic fertilizer (OF). This strain was identified as Bacillus amyloliquefaciens based on its morphological, physiological, and biochemical properties, as well as 16S rRNA analysis. Two kinds of antifungal lipopeptides (iturin and bacillomycin D) produced by W19 strain were detected and identified using HPLC–ESI-MS. Another lipopeptide, called surfactin, was also produced by the thick biological film forming W19 strain. In addition to lipopeptides, 18 volatile antifungal compounds with significant antagonistic effect against F. oxysporum were detected and identified using gas chromatography–mass spectrometer (GC–MS). The work described herein not only highlights how the bioorganic fertilizer with B. amyloliquefaciens can be used to control Fusarium wilt of banana but also examines some of the potential mechanisms involved in the biocontrol of Fusarium wilt.

Stomata in the epidermis of plants play essential roles in the regulation of photosynthesis and transpiration. Stomata open in response to blue light (BL) by phosphorylation-dependent activation of the plasma membrane (PM) H + -ATPase in guard cells. Under water stress, the plant hormone abscisic acid (ABA) promotes stomatal closure via the ABA-signaling pathway to reduce water loss. We established a chemical screening method to identify compounds that affect stomatal movements in Commelina benghalensis . We performed chemical screening using a protease inhibitor (PI) library of 130 inhibitors to identify inhibitors of stomatal movement. We discovered 17 PIs that inhibited light-induced stomatal opening by more than 50%. Further analysis of the top three inhibitors (PI1, PI2, and PI3; inhibitors of ubiquitin-specific protease 1, membrane type-1 matrix metalloproteinase, and matrix metalloproteinase-2, respectively) revealed that these inhibitors suppressed BL-induced phosphorylation of the PM H + -ATPase but had no effect on the activity of phototropins or ABA-dependent responses. The results suggest that these PIs suppress BL-induced stomatal opening at least in part by inhibiting PM H + -ATPase activity but not the ABA-signaling pathway. The targets of PI1, PI2, and PI3 were predicted by bioinformatics analyses, which provided insight into factors involved in BL-induced stomatal opening.

Background It is an integral property of sorghum ( Sorghum bicolor L.) to extensively release biological nitrification inhibitors (BNIs) under NH 4 + nutrition, in comparison to NO 3 − nutrition. Our previous research indicated that plasma membrane (PM) H + -ATPase activity was stimulated by NH 4 + and low rhizosphere pH, which in turn provided the driving force for BNIs release from sorghum roots. However, the regulatory mechanism of PM H + -ATPase itself in this regard is not fully elucidated. The present study thus aims at post-translational regulation of PM H + -ATPase via phosphorylation in response to NH 4 + nutrition and its functional link to the release of BNIs from sorghum roots. Methods A hydroponic system is used to grow sorghum with 1 mM NH 4 + or NO 3 − as N source at pH 3.0 or pH 7.0 in root medium for the analysis of PM H + -ATPase and BNIs release. The effect of NH 4 + on the regulation of PM H + -ATPase was further evaluated by the treatment of NO 3 − cultivated sorghum roots with different NH 4 + concentrations (0.1~1 mM). In addition, fusicoccin (a stimulator of PM H + -ATPase) and vanadate (an inhibitor of PM H + -ATPase) were added to check the effect of PM H + -ATPase phosphorylation on BNIs release. Further, methionine sulphoximine (MSX), which inhibits glutamine synthetase, is used to analyze the effect of ammonium transport/assimilation process on the PM H + -ATPase and BNIs release. Microsomal membrane protein isolated from these roots was used for the test of PM H + -ATPase phosphorylation level by western blot technique. Meanwhile, the root exudates were collected for the analysis of BNIs. Results Higher amount of PM H + -ATPase protein with higher phosphorylation level were detected in sorghum roots in response to NH 4 + and low rhizosphere pH, as compared to NO 3 − and high pH. Further, PM H + -ATPase protein amount and phosporylation level were dependent on the local supplement of NH 4 + (from 0.1 ~ 1 mM) to roots. Nevertheless, the enhanced posphorylation level under all of these treatments was significantly higher than the enhanced protein level of PM H + ATPase. Unlike protein level, phosphorylation level is closely correlated to the release of BNIs from sorghum roots. In addition, phosphorylation level of PM H + -ATPase adjusted by fusicoccin or vanadate directly affected the release of BNIs, irrespective of the protein level. In addition, ammonium assimilation inhibitor MSX caused decreased phosphorylation level of PM H + -ATPase without affecting the protein level, meanwhile inhibited the release of BNIs from sorghum roots. Conclusion Our research suggests that phosphorylation of PM H + -ATPase is one of the important regulation mechanisms involved in the release of BNIs from sorghum roots. NH 4 + stimulated PM H + -ATPase phosphorylation via excessive H + generated by NH 4 + assimilation in cytoplasm. The up regulation of PM H + -ATPase at post-translational level thus activated the H + pumping activity to provide the driving force for BNIs release. A new hypothesis is proposed to elucidate the interplay of these functionally inter-linked processes involving ammonium-uptake, −assimilation, and H + -pumps activation in PM on the release of BNIs from sorghum roots.

Aquaporins are involved in CO₂ transport from the leaf intercellular air space to the chloroplast, which contributes to CO₂ assimilation. However, the mechanism of CO₂ transport by rice (Oryza sativa L.) aquaporins is unknown. Here, we investigated the function of the aquaporin OsPIP1;2 in CO₂ diffusion-associated photosynthesis and phloem sucrose transport. Moreover, the grain yield of rice lines overexpressing OsPIP1;2 was determined. OsPIP1;2 was localized to the plasma membrane and the relative expression of OsPIP1;2 was approximately 5-fold higher in leaves in the presence of an elevated CO₂ concentration. Overexpression of OsPIP1;2 increased mesophyll conductance by approximately 150% compared with wild-type (WT) rice. The OsPIP1;2-overexpressing lines had higher biomass than the WT, possibly due to increased phloem sucrose transport. In addition, the grain yield of OsPIP1;2-overexpressing lines was approximately 25% higher than that of the WT in three-season field experiments, due to the increased numbers of effective tillers and spikelets per panicle. Our results suggest that OsPIP1;2 modulates rice growth and grain yield by facilitating leaf CO₂ diffusion, which increases both the net CO₂ assimilation rate and sucrose transport.

BP neural network (Back-Propagation Neural Network, BP-NN) is one of the most widely neural network models and is applied to fault diagnosis of power system currently. BP neural network has good self-learning and adaptive ability and generalization ability, but the operation process is easy to fall into local minima. Genetic algorithm has global optimization features, and crossover is the most important operation of the Genetic Algorithm. In this paper, we can modify the crossover of traditional Genetic Algorithm, using improved genetic algorithm optimized BP neural network training initial weights and thresholds, to avoid the problem of BP neural network fall into local minima. The results of analysis by an example, the method can efficiently diagnose network fault location, and improve fault-tolerance and grid fault diagnosis effect.

Background It is an integral property of sorghum (Sorghum bicolor L.) to extensively release biological nitrification inhibitors (BNIs) under NH.sub.4.sup.+ nutrition, in comparison to NO.sub.3.sup.- nutrition. Our previous research indicated that plasma membrane (PM) H.sup.+-ATPase activity was stimulated by NH.sub.4.sup.+ and low rhizosphere pH, which in turn provided the driving force for BNIs release from sorghum roots. However, the regulatory mechanism of PM H.sup.+-ATPase itself in this regard is not fully elucidated. The present study thus aims at post-translational regulation of PM H.sup.+-ATPase via phosphorylation in response to NH.sub.4.sup.+ nutrition and its functional link to the release of BNIs from sorghum roots. Methods A hydroponic system is used to grow sorghum with 1 mM NH.sub.4.sup.+ or NO.sub.3.sup.- as N source at pH 3.0 or pH 7.0 in root medium for the analysis of PM H.sup.+-ATPase and BNIs release. The effect of NH.sub.4.sup.+ on the regulation of PM H.sup.+-ATPase was further evaluated by the treatment of NO.sub.3.sup.-cultivated sorghum roots with different NH.sub.4.sup.+ concentrations (0.1~1 mM). In addition, fusicoccin (a stimulator of PM H.sup.+-ATPase) and vanadate (an inhibitor of PM H.sup.+-ATPase) were added to check the effect of PM H.sup.+-ATPase phosphorylation on BNIs release. Further, methionine sulphoximine (MSX), which inhibits glutamine synthetase, is used to analyze the effect of ammonium transport/assimilation process on the PM H.sup.+-ATPase and BNIs release. Microsomal membrane protein isolated from these roots was used for the test of PM H.sup.+-ATPase phosphorylation level by western blot technique. Meanwhile, the root exudates were collected for the analysis of BNIs. Results Higher amount of PM H.sup.+-ATPase protein with higher phosphorylation level were detected in sorghum roots in response to NH.sub.4.sup.+ and low rhizosphere pH, as compared to NO.sub.3.sup.- and high pH. Further, PM H.sup.+-ATPase protein amount and phosporylation level were dependent on the local supplement of NH.sub.4.sup.+ (from 0.1 ~ 1 mM) to roots. Nevertheless, the enhanced posphorylation level under all of these treatments was significantly higher than the enhanced protein level of PM H.sup.+ ATPase. Unlike protein level, phosphorylation level is closely correlated to the release of BNIs from sorghum roots. In addition, phosphorylation level of PM H.sup.+-ATPase adjusted by fusicoccin or vanadate directly affected the release of BNIs, irrespective of the protein level. In addition, ammonium assimilation inhibitor MSX caused decreased phosphorylation level of PM H.sup.+-ATPase without affecting the protein level, meanwhile inhibited the release of BNIs from sorghum roots. Conclusion Our research suggests that phosphorylation of PM H.sup.+-ATPase is one of the important regulation mechanisms involved in the release of BNIs from sorghum roots. NH.sub.4.sup.+ stimulated PM H.sup.+-ATPase phosphorylation via excessive H.sup.+ generated by NH.sub.4.sup.+ assimilation in cytoplasm. The up regulation of PM H.sup.+-ATPase at post-translational level thus activated the H.sup.+ pumping activity to provide the driving force for BNIs release. A new hypothesis is proposed to elucidate the interplay of these functionally inter-linked processes involving ammonium-uptake, -assimilation, and H.sup.+-pumps activation in PM on the release of BNIs from sorghum roots.