Allelopathy is an ecological phenomenon in which organisms interfere with each other. As a management strategy in agricultural systems, allelopathy can be mainly used to control weeds, resist pests, ...and disease and improve the interaction of soil nutrition and microorganisms. Volatile organic compounds (VOCs) are allelochemicals volatilized from plants and have been widely demonstrated to have different ecological functions. This review provides the recent advance in the allelopathic effects of VOCs on plants, such as growth, competition, dormancy, resistance of diseases and insect pests, content of reactive oxygen species (ROS), enzyme activity, respiration, and photosynthesis. VOCs also participate in plant-to-plant communication as a signaling substance. The main methods of collection and identification of VOCs are briefly summarized in this article. It also points out the disadvantages of VOCs and suggests potential directions to enhance research and solve mysteries in this emerging area. It is necessary to study the allelopathic mechanisms of plant VOCs so as to provide a theoretical basis for VOC applications. In conclusion, allelopathy of VOCs released by plants is a more economical, environmentally friendly, and effective measure to develop substantial agricultural industry by using the allelopathic effects of plant natural products.
The challenge of mitigating the decline in both yield and fruit quality due to the intrusion of powdery mildew (PM) fungus looms as a pivotal concern in the domain of bitter melon cultivation. Yet, ...the intricate mechanisms that underlie resistance against this pathogen remain inscrutable for the vast majority of bitter melon variants. In this inquiry, we delve deeply into the intricate spectrum of physiological variations and transcriptomic fluctuations intrinsic to the PM-resistant strain identified as ‘04-17-4’ (R), drawing a sharp contrast with the PM-susceptible counterpart, designated as ‘25-15’ (S), throughout the encounter with the pathogenic agent Podosphaera xanthii. In the face of the challenge presented by P. xanthii, the robust cultivar displays an extraordinary capacity to prolong the initiation of the pathogen’s primary growth stage. The comprehensive exploration culminates in the discernment of 6635 and 6954 differentially expressed genes (DEGs) in R and S strains, respectively. Clarification through the lens of enrichment analyses reveals a prevalence of enriched DEGs in pathways interconnected with phenylpropanoid biosynthesis, the interaction of plants with pathogens, and the signaling of plant hormones. Significantly, in the scope of the R variant, DEGs implicated in the pathways of plant-pathogen interaction phenylpropanoid biosynthesis, encompassing components such as calcium-binding proteins, calmodulin, and phenylalanine ammonia-lyase, conspicuously exhibit an escalated tendency upon the encounter with P. xanthii infection. Simultaneously, the genes governing the synthesis and transduction of SA undergo a marked surge in activation, while their counterparts in the JA signaling pathway experience inhibition following infection. These observations underscore the pivotal role played by SA/JA signaling cascades in choreographing the mechanism of resistance against P. xanthii in the R variant. Moreover, the recognition of 40 P. xanthii-inducible genes, encompassing elements such as pathogenesis-related proteins, calmodulin, WRKY transcription factors, and Downy mildew resistant 6, assumes pronounced significance as they emerge as pivotal contenders in the domain of disease control. The zenith of this study harmonizes multiple analytical paradigms, thus capturing latent molecular participants and yielding seminal resources crucial for the advancement of PM-resistant bitter melon cultivars.
Beam pumping motor system (BPMS) is a typical periodic potential energy load which is affected by factors such as down-hole load, mechanical transmission and geological structure. During a running ...cycle, the power fluctuates in a large range and multiple operating conditions where potential energy, electrical energy and kinetic energy are converted to one another and thus leads to lower system efficiency. For this type of load, a four-quadrant inverter is an effective method to improve the efficiency of the motor system. However, in practice, the two-quadrant variable frequency control is widely used due to its lower cost. The drawback of this control is the difficulty in realizing efficient conversion and utilization of electrical energy under the power generation mode, since the generated electrical energy is converted into thermal energy by the installed resistance brake inside the inverter, which causes additional energy consumption. To resolve this problem, this paper systematically studies the influence of frequency regulation on the load torque of BPMS, an automatic tracking frequency regulation method is then proposed. With this method, the controllable conversion between the kinetic and potential energy forms can be realized, and the fluctuation power under dynamic load conditions can also be smoothed. Meanwhile, energy consumption in power generation mode is also reduced effectively. The correctness and practicability of the proposed method are verified by the simulations and experiments of a standard oil well. The results show that, comparing to the traditional two-quadrant inverter, the proposed method can reduce the active power fluctuation of the system by about 20% under the premise of still using a two-quadrant inverter, and the power saving ratio is increased by more than 10%.
Introduction
Bananas are not only an important food crop for developing countries but also a major trading fruit for tropical and semitropical regions, maintaining a huge trade volume. Fusarium wilt ...of banana (FWB) caused by
Fusarium oxysporum
f. sp.
cubense
is becoming a serious challenge to the banana industry globally. Biological control has the potential to offer both effective and sustainable measures for this soil-borne disease.
Methods
In order to explore the biocontrol effects of the biological agent
Bacillus amyloliquefaciens
QST713 strain on banana plants, two cultivars, Brazilian and Yunjiao No. 1, with varied resistance to FWB, were used in greenhouse pot experiments.
Results
Results showed that the plant height and pseudostem diameter of banana-susceptible cultivar Brazilian increased by 11.68% and 11.94%, respectively, after QST713 application, while the plant height and pseudostem diameter of resistant cultivar Yunjiao No. 1 increased by 14.87% and 12.51%, respectively. The fresh weight of the two cultivars increased by 20.66% and 36.68%, respectively, indicating that this biological agent has potential effects on plant growth. Analysis of the rhizosphere soil microbial communities of two different cultivars of banana plants showed that TR4 infection and
B. amyloliquefaciens
QST713 strain application significantly affected the bacterial and fungal diversity of Yunjiao No. 1, but not in the cultivar Brazilian. In addition, TR4 infection and QST713 application changed the bacterial community composition of both banana cultivars, and the fungal community composition of Yunjiao No. 1 also changed significantly. Relevance analysis indicated that the relative richness of
Bacillus
and
Pseudomonas
in the rhizosphere of both cultivars increased significantly after QST713 application, which had a good positive correlation with plant height, pseudostem girth, aboveground fresh weight, leaf length, and leaf width.
Discussion
Therefore, the outcome of this study suggests that the biological agent QST713 strain has potential application in banana production for promoting plant growth and modification of soil microbial communities, particularly in the TR4-infected field.
Fusarium wilt of banana, especially Tropical Race 4 (TR4) is a major factor restricting banana production. Developing a resistant cultivar and inducing plant defenses by elicitor application are ...currently two of the best options to control this disease. Isotianil is a monocarboxylic acid amide that has been used as a fungicide to control rice blast and could potentially induce systemic acquired resistance in plants. To determine the control effect of elicitor isotianil on TR4 in different resistant cultivars, a greenhouse pot experiment was conducted and its results showed that isotianil could significantly alleviate the symptoms of TR4, provide enhanced disease control on the cultivars 'Baxi' and 'Yunjiao No.1' with control effect 50.14% and 56.14%, respectively. We compared the infection processes in 'Baxi' (susceptible cultivars) and 'Yunjiao No.1' (resistant cultivars) two cultivars inoculated with pathogen TR4. The results showed that TR4 hyphae could rapidly penetrate the cortex into the root vascular bundle for colonization, and the colonization capacity in 'Baxi' was significantly higher than that in 'Yunjiao No.1'. The accumulation of a large number of starch grains was observed in corms cells, and further analysis showed that the starch content in 'Yunjiao No. 1' as resistant cultivar was significantly higher than that in 'Baxi' as susceptible cultivar, and isotianil application could significantly increase the starch content in 'Baxi'. Besides, a mass of tyloses were observed in the roots and corms and these tyloses increased after application with isotianil. Furthermore, the total starch and tyloses contents and the control effect in the corms of 'Yunjiao No.1' was higher than that in the 'Baxi'. Moreover, the expression levels of key genes for plant resistance induction and starch synthesis were analyzed, and the results suggested that these genes were significantly upregulated at different time points after the application of isotianil. These results suggest that there are significant differences between cultivars in response to TR4 invasion and plant reactions with respect to starch accumulation, tyloses formation and the expression of plant resistance induction and starch synthesis related genes. Results also indicate that isotianil application may contribute to disease control by inducing host plant defense against TR4 infection and could be potentially used together with resistant cultivar as integrated approach to manage this destructive disease. Further research under field conditions should be included in the next phases of study.
Offsets between the primary and secondary coils of loosely coupled transformers (LCT) are attributable to the efficiency decline of the wireless power transfer (WPT) system. To improve the ...misalignment tolerance of efficiency in WPT system, this paper presents a LCT system with a movable intermediate coil and adjustable system frequency, which can promote the efficiency of the WPT system under misalignment condition. First, the influences of the position and compensation parameter of intermediate coil on the system efficiency during migration are summarized. The optimal compensation parameter and optimal position selection method of intermediate coil are proposed. Then, the influence of frequency on system efficiency is studied, and the detailed control strategy of intermediate coil's position and system frequency is proposed. A 3-kW prototype WPT with the proposed three-coil LCT is manufactured and experimental validations are also performed. The results show that the efficiency declines of three-coil LCT with the proposed control strategy is 1.8% when the lateral offsets reach 300mm, namely 43% of the outer diameter of coil.
Flavonoids are considered to be critical metabolites in regulating plant responses to abiotic stress. Chalcone synthase (CHS) catalyzes the first key step in the flavonoid biosynthesis pathway. ...However, there is no in-depth information on the sequence and functional analysis of CHS genes in Dendrobium catenatum. In this study, a total of 14 DcCHS genes were identified, encoding proteins of 349–504 amino acids in length, a protein molecular weight ranging between 39.08 and 56.56 kDa, and isoelectric points from 5.64 to 9.63. The DcCHS proteins were then divided into three groups according to their phylogenetic relationships. The members of each group had similar conserved motifs and gene structures. Quantitative real-time RT-PCR (RT-qPCR) analysis revealed that the DcCHS genes exhibited variable expression patterns in the different plant tissues evaluated. Furthermore, six genes were differentially expressed following exposure to abiotic stresses: DcCHS-6, DcCHS-5/-6, DcCHS-13/-14, and DcCHS-6/-8/-9/-13, which were specifically expressed in response to drought, heat, cold, and salt stress, respectively. This is the first genome-wide analysis of the CHS genes in D. catenatum, and our findings can provide essential information for a better understanding of the function of DcCHS genes, thus facilitating further research on D. catenatum stress tolerance.
GENERAL REGULATORY FACTOR (GRF) proteins play vital roles in the regulation of plant growth, development, and response to abiotic stress. However, little information is known for this gene family in ...cassava (
). In this study, 15 MeGRFs were identified from the cassava genome and were clustered into the ε and the non-ε groups according to phylogenetic, conserved motif, and gene structure analyses. Transcriptomic analyses showed eleven
with constitutively high expression in stems, leaves, and storage roots of two cassava genotypes. Expression analyses revealed that the majority of
showed transcriptional changes under cold, osmotic, salt, abscisic acid (ABA), and H₂O₂ treatments. Six
were found to be commonly upregulated by abiotic stress, ABA, and H₂O₂ treatments, which may be the converging points of multiple signaling pathways. Interaction network analysis identified 18 possible interactors of MeGRFs. Taken together, this study elucidates the transcriptional control of
in tissue development and the responses of abiotic stress and related signaling in cassava. Some constitutively expressed, tissue-specific, and abiotic stress-responsive candidate
genes were identified for the further genetic improvement of crops.
Auxin/indole‐3‐acetic acid proteins (Aux/IAAs) play important roles in auxin signaling pathways, with extensive involvement in plant development and plant response to abiotic and biotic stresses. ...Manihot esculenta (Cassava) is one of the most important biomass energy crops in tropical regions; however, the information about Aux/IAA proteins remain limited in cassava. In this study, 37 MeAux/IAA gene family members were identified in cassava and a phylogenetic analysis was performed. The transcript levels of MeAux/IAAs were commonly regulated by the pathogen Xanthomonas axonopodis pv manihotis (Xam), and some of them were specifically localized to the nucleus. Moreover, the overexpression of MeAux/IAAs confers an improved disease resistance against Xam in Nicotiana benthamiana, while MeAux/IAAs‐silenced plants show disease sensitivity against Xam in cassava, as evidenced by the leaf phenotype and leaf bacterial population. Consistent with the disease resistance, MeAux/IAAs regulated the transcript levels of PATHOGENESIS‐RELATED GENES (MePRs), reactive oxygen species accumulation and callose development in the plants' defense response. Taken together, gene profile and functional analysis identified several MeAux/IAAs as novel members in plant disease resistance, providing important information for further utilization of MeAux/IAAs.
The nuclear factor Y (NF-Y) transcription factor complex is important in plant growth, development and stress response. Information regarding this transcription factor complex is limited in cassava ...(Manihot esculenta). In this study, 15 MeNF-YAs, 21 MeNF-YBs and 15 MeNF-YCs were comprehensively characterized during plant defence.
Gene expression in MeNF-Ys was examined during interaction with the bacterial pathogen Xanthomonas axonopodis pv. manihotis (Xam). The yeast two-hybrid system was employed to investigate protein-protein interactions in the heterotrimeric NF-Y transcription factor complex. The in vivo roles of MeNF-Ys were revealed by virus-induced gene silencing (VIGS) in cassava.
The regulation of MeNF-Ys in response to Xam indicated their possible roles in response to cassava bacterial blight. Protein-protein interaction assays identified the heterotrimeric NF-Y transcription factor complex (MeNF-YA1/3, MeNF-YB11/16 and MeNF-YC11/12). Moreover, the members of the heterotrimeric NF-Y transcription factor complex were located in the cell nucleus and conferred transcriptional activation activity to the CCAAT motif. Notably, the heterotrimeric NF-Y transcription factor complex positively regulated plant disease resistance to Xam, confirmed by a disease phenotype in overexpressing plants in Nicotiana benthamiana and VIGS in cassava. Consistently, the heterotrimeric NF-Y transcription factor complex positively regulated the expression of pathogenesis-related genes (MePRs).
The NF-Y transcription factor complex (MeNF-YA1/3, MeNF-YB11/16 and MeNF-YC11/12) characterized here was shown to play a role in transcriptional activation of MePR promoters, contributing to the plant defence response in cassava.
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