Calcium/Calmodulin-Mediated Defense Signaling: What Is Looming on the Horizon for AtSR1/CAMTA3-Mediated Signaling in Plant Immunity

Calcium (Ca2+) signaling in plant cells is an essential and early event during plant-microbe interactions. The recognition of microbe-derived molecules activates Ca2+ channels or Ca2+ pumps that trigger a transient increase in Ca2+ in the cytoplasm. The Ca2+ binding proteins (such as CBL, CPK, CaM, and CML), known as Ca2+ sensors, relay the Ca2+ signal into down-stream signaling events, e.g., activating transcription factors in the nucleus. For example, CaM and CML decode the Ca2+ signals to the CaM/CML-binding protein, especially CaM-binding transcription factors (AtSRs/CAMTAs), to induce the expressions of immune-related genes. In this review, we discuss the recent breakthroughs in down-stream Ca2+ signaling as a dynamic process, subjected to continuous variation and gradual change. AtSR1/CAMTA3 is a CaM-mediated transcription factor that represses plant immunity in non-stressful environments. Stress-triggered Ca2+ spikes impact the Ca2+-CaM-AtSR1 complex to control plant immune response. We also discuss other regulatory mechanisms in which Ca2+ signaling activates CPKs and MAPKs cascades followed by regulating the function of AtSR1 by changing its stability, phosphorylation status, and subcellular localization during plant defense.

Design of an Artificial Intelligence of Things Based Indoor Planting Model for Mentha Spicata

In recent years, many large-scale plantings have become refined small-scale or home plantings. The rapid progress of agriculture technologies and information techniques enables people to control the growth of agricultural products well. Hence, this study proposes an Artificial Intelligence of Things (AIoT) based Plant Pot Design for planting edible mint in an office setting, which is called APPD. APPD is composed of intelligent gardens and a cloud-based service platform. An intelligent garden is deployed an Arduino with multiple sensors to monitor and control plant pots of the edible mint, Mentha spicata. The cloud-based service platform provides a Case-Based Reasoning (CBR) inference engine with a database for adjustment influence factors. This study discusses eight growing statuses of Mentha spicata with different illumination, photometric exposure, and moisture content, designed for an office environment. Evaluation results indicate that Mentha spicata with 16 h red–blue lighting and 50% moisture content makes a maximum 5% mint extract of the total weight of the mint leaves. Finally, APPD can be a reference model for researchers and engineers.

Changing in the production of anticancer drugs (vinblastine and vincristine) in Catharanthus roseus (L.) G. Don by potassium and ascorbic acid treatments

Catharanthus roseus seedling was treated with different concentrations (1.5, 3.16, 15, and 30 mmol) and forms (K₂SO₄ and KNO₃) of potassium (K⁺) via Hoagland’s nutrient solution. Ascorbic acid (AsA) was sprayed twice (plant days 68 and 78) with different concentrations (750 and 1 500 mg/L) on the leaves. Vinblastine, vincristine, tryptophan contents, D4H and DAT genes expression, peroxidase activity, and H₂O₂ content of leaves were measured. Potassium in KNO₃ form increased vinblastine (60%) and vincristine (50%), compared to 30% and 20% using K₂SO₄. Vinblastine and vincristine inhibit microtubule assembly and ultimately metaphase-arrested caused by the polymerisation. The genes expression was higher 3 times in KNO₃ and 2.5 times in K₂SO₄ in excess of K⁺. Foliar application of 750 mg/L AsA led to an increase in vinblastine (20%) and vincristine (16%). Both concentrations of AsA had the same additional effect on the expression of D4H and DAT about 30% and 60%, respectively, compared to the control plant. Tryptophan decreased 2.5 times in excess of K⁺ and 35% due to the exterior of AsA. H₂O₂ decreased while peroxidase activity increased along with AsA treatment. A positive interaction existed between the K⁺ and AsA on the amount of vinblastine, vincristine, tryptophan, and gene expression.

Field application of nanoliposomes delivered quercetin by inhibiting specific hsp70 gene expression against plant virus disease

Background The annual economic loss caused by plant viruses exceeds 10 billion dollars due to the lack of ideal control measures. Quercetin is a flavonol compound that exerts a control effect on plant virus diseases, but its poor solubility and stability limit the control efficiency. Fortunately, the development of nanopesticides has led to new ideas. Results In this study, 117 nm quercetin nanoliposomes with excellent stability were prepared from biomaterials, and few surfactants and stabilizers were added to optimize the formula. Nbhsp70er-1 and Nbhsp70c-A were found to be the target genes of quercetin, through abiotic and biotic stress, and the nanoliposomes improved the inhibitory effect at the gene and protein levels by 33.6 and 42%, respectively. Finally, the results of field experiment showed that the control efficiency was 38% higher than that of the conventional quercetin formulation and higher than those of other antiviral agents. Conclusion This research innovatively reports the combination of biological antiviral agents and nanotechnology to control plant virus diseases, and it significantly improved the control efficiency and reduced the use of traditional chemical pesticides. Graphical Abstract

Biocontrol of Rice Diseases by Microorganisms

Rice is responsible for the stable crop of 3 billion people worldwide, about half of Asian depends on it, and rice is grown in more than 100 countries. Rice diseases can lead to devastating economic loss by decreasing yield production, disturbing a stable food supply and demand chain. The most commonly used method to control rice disease is chemical control. However, misuse of chemical control can cause environmental pollution, residual toxicity, and the emergence of chemical-resistant pathogens, the deterioration of soil quality, and the destruction of biodiversity. In order to control rice diseases, research on alternative biocontrol is actively pursued including microorganism-oriented biocontrol agents. Microbial agents control plant disease through competition with and antibiotic effects and parasitism against plant pathogens. Microorganisms isolated from the rice rhizosphere are studied comprehensively as biocontrol agents against rice pathogens. Bacillus sp., Pseudomonas sp., and Trichoderma sp. were reported to control rice diseases, such as blast, sheath blight, bacterial leaf blight, brown spot, and bakanae diseases. Here we reviewed the microorganisms that are studied as biocontrol agents against rice diseases.

Clathrin-mediated Endocytosis Facilitates Internalization of Magnaporthe oryzae Effectors into Rice Cells

Many filamentous eukaryotic plant pathogens, such as fungi and oomycetes, deliver effectors into living plant cells to suppress defenses and control plant processes needed for infection. To date, little is known about the mechanism by which these pathogens translocate effector proteins across the plasma membrane into the plant cytoplasm. The blast fungus Magnaporthe oryzae secretes cytoplasmic effectors into a specialized biotrophic interfacial complex (BIC) before translocation. Here we show that cytoplasmic effectors within BICs are packaged into dynamic vesicles that can occasionally be found separated from BICs in the host cytoplasm. Live cell imaging with fluorescently-labelled rice lines, showed that BICs are enriched in plant plasma membrane, actin, and Clathrin Light Chain-1, a marker for clathrin-mediated endocytosis (CME). We report that a novel cytoplasmic effector, Bas83, labels empty membrane vesicles surrounding BICs. Inhibition of CME using VIGS and chemical treatments results in a distinctive swollen BIC phenotype lacking effector vesicles. In contrast, fluorescent marker co-localization, VIGS and chemical inhibitor studies failed to implicate clathrin-independent endocytosis in effector vesicle formation. Taken together, this study provides evidence that cytoplasmic effector translocation is mediated by clathrin-mediated endocytosis in BICs and suggests a role for M. oryzae effectors in co-opting plant endocytosis.

Robust Stabilization via Super-Stable Systems Techniques

In this paper, we propose a direct method for the synthesis of robust systems operating under parametric uncertainty of the control plant model. The developed robust control procedures are based on the assumption that the structural properties of the nominal system are conservated over the entire range of parameter changes. The invariant-to-parametric-uncertainties transformation of the initial model to a regular form makes it possible to use the concept of super-stable systems for the synthesis of a stabilizing feedback. It is essential that the synthesis of super-stable systems is carried out not on the basis of assigning eigenvalues to the matrix of the close-loop system, but in terms of its elements. The proposed approach is applicable to a wide class of linear systems with parametric uncertainties and provides a given degree of stability.

Occurrence of Antibiotic-Resistant Staphylococcus spp. in Orange Orchards in Thailand

Background: The widespread indiscriminate application of antibiotics to food crops to control plant disease represents a potential human health risk. In this study, the presence of antibiotic-resistant staphylococci associated with workers and orange orchard environments was determined. A total of 20 orchards (orange and other fruits) were enrolled in the study. Trees in the orange orchards were treated with ampicillin on a pre-determined schedule. Environmental samples (n = 60) included soil, water, and oranges; 152 hand and nasal samples were collected from 76 healthy workers. Antibiotic susceptibility profiles were determined for all staphylococcal isolates. Results: This investigation revealed that of the total Staphylococcus spp. recovered from the orange orchard, 30% (3/10) were resistant to erythromycin, 20% (2/10) were resistant to ampicillin, and 20% (2/10) resistant to both erythromycin and ampicillin. Conclusion: The application of antibiotics to orange trees in open production environments to halt the spread of bacterial disease presents risks to the environment and creates health concerns for Thai farmers using those agents. ARB on crops such as oranges may enter the global food supply and adversely affect public health.

Control of Fusarium Wilt Using Streptomyces griseus with Plant Growth-Promoting Effect on Tomato

The efficacy of antagonistic Streptomyces griseus was evaluated against tomato wilt disease incited by Fusarium oxysporum. Among the different formulations, Streptomyces griseus with chitin amended formulation showed effective increase in seed germination and seedling vigour. Further, talc-based formulations of S. griseus mixed with or without chitin was developed and tested under greenhouse conditions. Lowest disease severity of 19.1% was observed in plants treated with self fusant (SFSg 5) S. griseus suspension (root dipping – 9 x 108 cfu / mL) followed by 19.5% in treatment of chitin amended S. griseus (root dipping – 9 x 108 cfu/mL) was recorded over control. Plant growth of the treated traits were analyzed and compared with control. The shoot length, root length, leaf area was increased significantly over the controls by the treatment of self fusant (SFSg 5) S. griseus suspension followed by nearby values were reached in chitin amended S. griseus was recorded. The chemical treatments had less effect compared with these formulations. Histochemical studies showed that cambium layers, xylem vessels per bundle, and the vessel diameter decreased in the plants inoculated with F. oxysporum over control and changes in variables were observed in infected plants treated with S. griseus. In conclusion, S. griseus can be a potential biocontrol agent against F. oxysporum for better crop production practices.