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The TATA box and 5′untranslated region (5′UTR) are critical regulatory elements that influence gene expression in plant defense responses. In rice (Oryza sativa), these elements modulate transcriptional and translational regulation during infection by the blast pathogen Magnaporthe oryzae. This study investigates the functional significance of the TATA box and 5′UTR in rice defense signaling by analyzing promoter and 5′UTR variations in key defense-related genes. Through comparative genomics, expression profiling, and mutagenesis assays, we show that 60% of defense genes with specific TATA box motifs exhibit enhanced transcription, while 5′UTR variants increase translational efficiency by up to 2-fold, contributing to blast resistance. These regulatory mechanisms provide a framework for targeted breeding and biotechnological interventions to enhance disease resistance in rice. Our findings highlight the importance of these elements in fine-tuning rice immune responses and suggest potential targets for improving disease resistance in rice cultivars.

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.

Plant invasions can have long-lasting impacts on soil nitrification, which plays a critical role in nutrient cycling and plant growth. This review examines the legacy effects of plant invasion on soil nitrification, focusing on the underlying mechanisms, context dependence, and implications for management. We synthesize literature on the positive, negative and neutral legacy effects of plant invasion on soil nitrification, highlighting the complexity of these effects and the need for further research to fully understand them. Positive legacy effects include increased soil microbial biomass or activity, potentially enhancing nutrient availability for plants. However, negative legacy effects, like reduced nitrifier abundance, can result in decreased soil nitrification rates and nutrient availability. In some cases, changes to nitrification during active invasion appear transitory after the removal of invasive plants, indicating neutral short-term legacies. We discuss the context dependence of legacy effects considering factors, including location, specific invasive plant species, and other environmental conditions. Furthermore, we discuss the implications of these legacy effects for management and restoration strategies, such as the removal or control of invasive plants, and potential approaches for restoring ecosystems with legacy effects on soil nitrification. Finally, we highlight future research directions, including further investigation into the mechanisms and context dependence of legacy effects, and the role of plant–microbe interactions. Overall, this review provides insights into the legacy effects of plant invasion on soil nitrification and their implications for ecosystems.

Background Sorghum roots release two categories of biological nitrification inhibitors (BNIs) – hydrophilic-BNIs and hydrophobic-BNIs. Earlier research indicated that rhizosphere pH and plasma membrane (PM) H+ATPase are functionally linked with the release of hydrophilic BNIs, but the underlying mechanisms are not fully elucidated. This study is designed to reveal further insights into the regulatory mechanisms of BNIs release in root systems, using three sorghum genetic stocks. Methods Sorghum plants were grown in a hydroponic system with pH of nutrient solutions ranging from 3.0 9.0. Pharmacological agents [(fusicoccin and vanadate) and anion-channel blockers (–niflumic acid (NIF) and anthracene-9-carboxylate (A9C)] were applied to root exudate collection solutions; BNI activity was determined with luminescent Nitrosomonas europaea bioassay. Sorgoleone levels in root exudates and H+ excretion from roots were determined. Two-phase partitioning system is used to isolate root plasma membrane (PM) and H+ ATPase activity was determined. Results A decrease in rhizosphere pH improved the release of hydrophilic-BNIs from roots of all the three sorghum genotypes, but had no effect on the release of hydrophobic-BNIs. Hydrophobic-BNI activity and sorgoleone levels in root-DCM wash are positively correlated. Fusicoccin promoted H+extrusion and stimulated the release of hydrophilic-BNIs. Vanadate, in contrast, suppressed H+ extrusion and lowered the release of hydrophilic-BNIs. Anion-channel blockers did not inhibit the release of hydrophilic BNIs, but enhanced H+-extrusion and hydrophilic-BNIs release. Conclusion Rhizosphere pH has a major influence on hydrophilic-BNIs release, but not on the release of hydrophobic-BNIs. The low rhizosphere pH stimulated PM-H+ ATPase activity; H+-extrusion is closely coupled with hydrophilic-BNIs release. Anion-channel blockers stimulated H+ extrusion and hydrophilic-BNIs release. Our results indicate that some unknown membrane transporters are operating the release of protonated BNIs, which may compensate for charge balance when transport of other anions is suppressed using anion-channel blockers. A new hypothesis is proposed for the release of hydrophilic-BNIs from sorghum roots.

Excessive nitrogen (N) application and reduced nitrogen use efficiency (NUE) are the key reasons behind N notoriety worldwide, including in Pakistan. We estimated the changes in NUE of Pakistan by calculating the N budget of Pakistan's agriculture during the last 53 years (1961-2013). A more than ten-fold increase in N input (including N fertilizer, biological N fixation, manure, and atmospheric deposition) from 408 GgNyr−1 (1961-1965) to 4636 GgNyr−1 (2009-2013) highlights the fact that Pakistan is experiencing a massive expansion of N consumption. Significantly declining NUE (from 58% to 23%) and sharply increasing surplus N (171 GgNyr−1 to 3581 GgNyr−1) may cause N-related environment problems in the future if not handled immediately. Escalating gaseous N emissions of NH3, N2O, and NO (70, 10, and 1 GgNyr−1 to 1023, 155, and 46 GgNyr−1, respectively) is already posing a serious threat in terms of impaired air quality. There is a dire need to devise/adapt strategies and consistent policies for improving NUE, using proper management approaches at the grass root level and applying appropriate legislative measures for judicious N use as per crops requirements. Moreover, promotion of a balanced use of fertilizers would help in improving NUE in agriculture.

Root exudates of the invasive Solidago canadensis and the cereal crop Sorghum bicolor (L.) Moench cv. ‘Hybridsorgo’ were tested for allelopathic interactions against native and invasive plant species in a controlled environment. After the surface was sterilized, the seeds of two invasive species (Bromus sterilis and Veronica persica) and two native species (Youngia japonica and Rumex acetosa) were germinated and transplanted into the soil (1:1 mixture of coco peat and sand) that had been conditioned for one month by the cultivation of Solidago canadensis and Sorghum bicolor, both in combination or as unplanted controls. After an additional eight weeks of growth, morphometric measurements of the shoot and root, including foliar characteristics and above- and below-ground biomass accumulation, were performed. The results revealed significant inhibitory effects of root exudates released by Sorghum bicolor and Solidago canadensis on native species’ productivity and physiology. The invasive species exhibited variable growth responses, with Veronica persica showing reduced shoot and root expansion, but Bromus sterilis revealed increased shoot and root biomass allocation and nutrition under the exudate treatments. Exudates from Solidago canadensis and Sorghum bicolor together showed synergistic negative effects on native species, while they promoted growth and nutrition in Veronica persica. Taken together, the differential species responses indicate that the tested native species were more sensitive to the allelopathic compounds than the invasive species, which is in line with the theory of novel weapons. The legacy effects of root exudates of both Sorghum bicolor and Solidago canadensis could promote invasive establishment through imposing allelochemical interference competition against native plant species. Understanding the specific allelopathic mechanisms may help with the development of integrated strategies for managing invasive species.

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.

Invasive plant species possess remarkable abilities to establish themselves in new environments and to displace native species. Their success can be attributed to various physiological and biochemical mechanisms, allowing them to tolerate adverse environmental conditions, including high lead (Pb) toxicity. Comprehension of the mechanisms responsible for Pb tolerance in invasive plants is still limited, but it is rapidly evolving. Researchers have identified several strategies in invasive plants to tolerate high levels of Pb. This review provides an overview of the current understanding of the ability of invasive species to tolerate or even accumulate Pb in plant tissues, including vacuoles and cell walls, as well as how rhizosphere biota (bacteria and mycorrhizal fungi) help them to enhance Pb tolerance in polluted soils. Furthermore, the article highlights the physiological and molecular mechanisms regulating plant responses to Pb stress. The potential applications of these mechanisms in developing strategies for remediating Pb-contaminated soils are also discussed. Specifically, this review article provides a comprehensive understanding of the current status of research on the mechanisms involved in Pb tolerance in invasive plants. The information presented in this article may be useful in developing effective strategies for managing Pb-contaminated soils, as well as for developing more resilient crops in the face of environmental stressors.

Due to the rapid development of China’s economy, the demand for wood is steadily increasing. Eucalyptus species have been introduced in large quantities because of their fast growth, strong adaptability, and wide utility. To understand the phenological changes in introduced Eucalyptus in its new range, we carried out a field investigation to examine leaf functional and chemical defense traits of three introduced species (E. saligna, E. grandis and E. robusta) over latitudinal and altitudinal gradients in southern China. We sampled multiple stands of each species, and measured the leaf physical characteristics (e.g., leaf width, leaf thickness, and specific leaf area [SLA]), leaf nitrogen (N) and phosphorus (P) content, and phenolic compounds. We found that many functional traits (e.g., leaf size and thickness) decreased at lower latitudes, especially in E. grandis, possibly to reduce heat and water loss under higher temperatures. In E. grandis, we found that leaf P was lower at higher latitudes and altitude, and phenolics increased with elevation, while in E. robusta, both leaf N and P decreased with altitude. These findings suggested that both species were more conservative in resource allocation, with E. grandis possessing enhanced chemical defenses in response to the conditions experienced at higher elevations. In addition, we found the tree populations at the northern range limit of E. robusta had lower SLA, suggesting a more conservative growth strategy, In contrast, small populations in the northern part of the ranges of E. grandis had higher SLA, indicating range expansion at the edge of the species’ geographic distribution. Overall, it is particularly important to consider intraspecific trait differences across wide geographic areas when studying the spread of invasive species in the new range.

Invasive species and rapid climate change are affecting the control of new plant diseases and epidemics. To effectively manage these diseases under changing environmental conditions, a better understanding of pathophysiology with holistic approach is needed. Multiomics approaches can help us to understand the relationship between plants and microbes and construct predictive models for how they respond to environmental stresses. The application of omics methods enables the simultaneous analysis of plant hosts, soil, and microbiota, providing insights into their intricate relationships and the mechanisms underlying plant–microbe interactions. This can help in the development of novel strategies for enhancing plant health and improving soil ecosystem functions. The review proposes the use of omics methods to study the relationship between plant hosts, soil, and microbiota, with the aim of developing a new technique to regulate soil health. This approach can provide a comprehensive understanding of the mechanisms underlying plant–microbe interactions and contribute to the development of effective strategies for managing plant diseases and improving soil ecosystem functions. In conclusion, omics technologies offer an innovative and holistic approach to understanding plant–microbe interactions and their response to changing environmental conditions.