Resistant Rice Plants Research Articles

Limonene enhances rice plant resistance to a piercing-sucking herbivore and rice pathogens.

Terpene synthases (TPSs) are key enzymes in terpenoids synthesis of plants and play crucial roles in regulating plant defence against pests and diseases. Here, we report the functional characterization of OsTPS19 and OsTPS20, which were upregulated by the attack of brown planthopper (BPH). BPH female adults performed concentration-dependent behavioural responses to (S)-limonene showing preference behaviour at low concentrations and avoidance behaviour at high concentrations. Overexpression lines of OsTPS19 and OsTPS20, which emitted higher amounts of the monoterpene (S)-limonene, decreased the hatching rate of BPH eggs, reduced the lesion length of sheath blight caused by Rhizoctonia solani and bacterial blight caused by Xanthomonas oryzae. While knockout lines of OsTPS19 and OsTPS20, which emitted lower amounts of (S)-limonene, were more susceptible to these pathogens. Overexpression of OsTPS19 and OsTPS20 in rice plants had adverse effects on the incidence of BPH, rice blast, and sheath blight in the field and had no significant impacts on rice yield traits. OsTPS19 and OsTPS20 were found to be involved in fine-tuning the emission of (S)-limonene in rice plants and play an important role in defence against both BPH and rice pathogens.

Experimental teaching design of CRISPR/Cas9 technology in rice breeding application

The CRISPR/Cas9 gene editing technology has proven to be valuable in crop breeding applications. Understanding and mastering this technology will provide a strong foundation for students majoring in biology, agronomy, and related fields to engage in scientific research and work. To incorporate CRISPR/Cas9 technology into experimental teaching courses at colleges, an innovative teaching experiment entitled "Enhancing the resistance of rice plants to bacterial blight disease using CRISPR/Cas9 technology" was designed. The experiment allows students to deepen their understanding of the basic principles of CRISPR/Cas technology, acquire proficiency in its protocol, and learn to apply the technology for targeted molecular breeding of rice. It not only expands students' knowledge and skills, but also promotes the reform and innovation of experimental teaching methods.

Effect of abscisic acid on rice defense mechanism against Fusarium oxysporum

Fusarium oxysporum is one of the most destructive pathogens which causes rice seedling blight. ABA is part of a large signaling system that provides an effective system against microbial and environmental manipulations. The role of ABA in plant defense mechanisms is not clear. In this experiment, we prove the role of abscisic acid (ABA) in boosting rice plant resistance against F. oxysporum and optimizing ABA concentrations against F. oxysporum. This study is divided into two experiments. In the first experiment, we used various ABA concentrations of 0.0, 0.05, 0.1, 0.2, and 0.25 mmol/L under F. oxysporum stress. In the second experiment, we use Fluridone FLD as an ABA inhibitor with the following treatments, (F) is only applied with F. oxysporum (ABA+F), abscisic acid with F. oxysporum (ABAI+F), ABA inhibitor Fluridone with F. oxysporum (ABAI), where only ABA inhibitor Fluridone was applied and CK was used as a control. The results revealed that all the plants treated with ABA exhibit better performance against F. oxysporum, except those treated without ABA. ABA concentrations of 0.2 mmol/L effectively decreased the disease index and disease incidence rate as well as improved the quality of seedlings. ABA effectively increased the activity of defense-related enzymes like PPO, POD, PAL and SOD. ABA also lowers down the MDA content which proves its effectiveness against F. oxysporum. ABA resistance was also proved by plants treated with the abscisic acid inhibitor ABAI (Fluridone FLD). The ABA inhibitor reduced the rice resistance to F. oxysporum, by conforming the expression of defense-related genes PRB1-3, PRBI-2 and Xa39(t). These gene expressions indicate the involvement of ABA in plant defense system.

Disease resistance features of the executor R gene Xa7 reveal novel insights into the interaction between rice and Xanthomonas oryzae pv. oryzae.

Bacterial blight (BB), caused by Xanthomonas oryzae pv. oryzae (Xoo), is a widespread and destructive disease in rice production. Previously, we cloned an executor R gene, Xa7, which confers durable and broad-spectrum resistance to BB. Here, we further confirmed that the transcription activator-like effector (TALE) AvrXa7 in Xoo strains could directly bind to the effector-binding element (EBE) in the promoter of the Xa7 gene. Other executor R genes (Xa7, Xa10, Xa23, and Xa27) driven by the promoter of the Xa7 gene could be activated by AvrXa7 and trigger the hypersensitive response (HR) in tobacco leaves. When the expression of the Xa23 gene was driven by the Xa7 promoter, the transgenic rice plants displayed a similar resistance spectrum as the Xa7 gene, demonstrating that the disease resistance characteristics of executor R genes are mainly determined by their induction patterns. Xa7 gene is induced locally by Xoo in the infected leaves, and its induction not only inhibited the growth of incompatible strains but also enhanced the resistance of rice plants to compatible strains, which overcame the shortcomings of its race-specific resistance. Transcriptome analysis of the Xa7 gene constitutive expression in rice plants displayed that Xa7-mediated disease resistance was related to the biosynthesis of lignin and thus enhanced resistance to Xoo. Overall, our results provided novel insights and important resources for further clarifying the molecular mechanisms of the executor R genes.

Combined miRNA and mRNA sequencing reveals the defensive strategies of resistant YHY15 rice against differentially virulent brown planthoppers.

The brown planthopper (BPH) poses a significant threat to rice production in Asia. The use of resistant rice varieties has been effective in managing this pest. However, the adaptability of BPH to resistant rice varieties has led to the emergence of virulent populations, such as biotype Y BPH. YHY15 rice, which carries the BPH resistance gene Bph15, exhibits notable resistance to biotype 1 BPH but is susceptible to biotype Y BPH. Limited information exists regarding how resistant rice plants defend against BPH populations with varying levels of virulence. In this study, we integrated miRNA and mRNA expression profiling analyses to study the differential responses of YHY15 rice to both avirulent (biotype 1) and virulent (biotype Y) BPH. YHY15 rice demonstrated a rapid response to biotype Y BPH infestation, with significant transcriptional changes occurring within 6 hours. The biotype Y-responsive genes were notably enriched in photosynthetic processes. Accordingly, biotype Y BPH infestation induced more intense transcriptional responses, affecting miRNA expression, defenserelated metabolic pathways, phytohormone signaling, and multiple transcription factors. Additionally, callose deposition was enhanced in biotype Y BPH-infested rice seedlings. These findings provide comprehensive insights into the defense mechanisms of resistant rice plants against virulent BPH, and may potentially guide the development of insect-resistant rice varieties.

The deterioration of starch physiochemical and minerals in high-quality indica rice under low-temperature stress during grain filling.

Low temperatures during the grain-filling phase have a detrimental effect on both the yield and quality of rice grains. However, the specific repercussions of low temperatures during this critical growth stage on grain quality and mineral nutrient composition in high-quality hybrid indica rice varieties have remained largely unexplored. The present study address this knowledge gap by subjecting eight high-quality indica rice varieties to two distinct temperature regimes: low temperature (19°C/15°C, day/night) and control temperature (28°C/22°C) during their grain-filling phase, and a comprehensive analysis of various quality traits, with a particular focus on mineral nutrients and their interrelationships were explored. Exposure of rice plants to low temperatures during early grain filling significantly impacts the physicochemical and nutritional properties. Specifically, low temperature increases the chalkiness rate and chalkiness degree, while decreases starch and amylopectin content, with varying effects on amylose, protein, and gelatinization temperature among rice varieties. Furthermore, crucial parameters like gelatinization enthalpy (ΔH), gelatinization temperature range (R), and peak height index (PHI) all significantly declined in response to low temperature. These detrimental effects extend to rice flour pasting properties, resulting in reduced breakdown, peak, trough, and final viscosities, along with increased setback. Notably, low temperature also had a significant impact on the mineral nutrient contents of brown rice, although the extent of this impact varied among different elements and rice varieties. A positive correlation is observed between brown rice mineral nutrient content and factors such as chalkiness, gelatinization temperature, peak viscosity, and breakdown, while a negative correlation is established with amylose content and setback. Moreover, positive correlations emerge among the mineral nutrient contents themselves, and these relationships are further accentuated in the context of low-temperature conditions. Therefore, enhancing mineral nutrient content and increasing rice plant resistance to chilling stress should be the focus of breeding efforts to improve rice quality.

Ability of commercial Beauveria bassiana to suppress the brown planthopper attack by inducing resistance into different rice variety

Abstract. Liswandi A, Syahrawati M, Hamid H, Arneti, Rinaldi J. 2023. Ability of commercial Beauveria bassiana to suppress the brown planthopper attack by inducing resistance into different rice variety. Biodiversitas 24: 6704-6710. Beauveria bassiana (Bb) is one of the biological agents for controlling the Brown Planthopper (BPH), Nilaparvata lugens, which is generally applied directly to BPH. Nowadays, it is also used to induce resistance in rice plants; this ability has never been tested on commercial B. bassiana. The research aimed to study the effect of different rice varieties and induced resistance of commercial Bb on BPH and rice plants. The study used a Factorial Completely Randomized Design (FCRD). The first factor was the difference in rice varieties (IR 42, Cisokan, Batang Piaman), and the second factor was the soaking of the seeds and roots by commercial Bb (with commercial Bb, without commercial Bb). The results showed no interaction between rice variety and commercial Bb against BPH and rice plants. Commercial Bb reduced the attack intensity of BPH (13.31%); meanwhile, different rice varieties influenced BPH mortality, colonization, and plant growth. The Cisokan variety was better at suppressing the BPH population (45%) and suitable for colonization by commercial Bb. The IR 42 variety was more responsive than other varieties in accepting the presence of commercial Bb (16%).

Determining the potential of sonic bloom in inducing rice resistance (Oryza sativa) against the attack of bacterial leaf blight disease caused by Xanthomonas oryzae

Xanthomonas oryzae which causes bacterial leaf blight disease is one of the main pathogens that attack rice crops. The threat of losing rice yields due to X. oryzae needs to be avoided by implementing appropriate control strategies. Sonic bloom has the potential to induce plant immunity against diseases. Hence, this study aimed to examine the potential of sonic bloom in inducing rice resistance to bacterial leaf blight. The experiment was arranged in a Randomized Block Design (RBD) with five treatments and three replications. The treatments consisted of several frequencies, namely PR (0.5 - 1 kHz and inoculated with X. oryzae), PS (3 - 5 kHz and inoculated with X. oryzae), PT (7 - 10 kHz and inoculated with X. oryzae), KP (inoculated with X. oryzae without sonic bloom treatment), KN (no bacterial inoculation and sonic bloom treatment). The results showed that all sonic bloom treatments (LF, MF, HF) had a significant effect on increasing the intensity of BLB disease in rice plants. This showed that sonic bloom in this range does not have the potential to induce rice plant resistance to BLB. Further research to find out the causes of this is needed.

Novel Insights into Exogenous Phytohormones: Central Regulators in the Modulation of Physiological, Biochemical, and Molecular Responses in Rice under Metal(loid) Stress.

Rice (Oryza sativa) is a research model for monocotyledonous plants. Rice is also one of the major staple foods and the primary crop for more than half of the world's population. Increasing industrial activities and the use of different fertilizers and pesticides containing heavy metals (HMs) contribute to the contamination of agriculture fields. HM contamination is among the leading causes that affect the health of rice plants by limiting their growth and causing plant death. Phytohormones have a crucial role in stress-coping mechanisms and in determining a range of plant development and growth aspects during heavy metal stress. This review summarizes the role of different exogenous applications of phytohormones including auxin, cytokinin, gibberellins, ethylene, abscisic acid, strigolactones, jasmonates, brassinosteroids, and salicylic acids in rice plants for mitigating heavy metal stress via manipulation of their stress-related physiological and biochemical processes, and alterations of signaling and biosynthesis of genes. Exogenous administration of phytohormones and regulation of endogenous levels by targeting their biosynthesis/signaling machineries is a potential strategy for protecting rice from HM stress. The current review primarily emphasizes the key mechanistic phytohormonal-mediated strategies for reducing the adverse effects of HM toxicity in rice. Herein, we have provided comprehensive evidence for the effective role of exogenous phytohormones in employing defense responses and tolerance in rice to the phytotoxic effects of HM toxicity along with endogenous hormonal crosstalk for modulation of subcellular mechanisms and modification of stress-related signaling pathways, and uptake and translocation of metals. Altogether, this information offers a systematic understanding of how phytohormones modulate a plant's tolerance to heavy metals and may assist in directing the development of new approaches to strengthen rice plant resistance to HM toxicity.

Co-expression of four penaeidins in transgenic rice seeds: an alternative strategy for substitute antibiotic agricultural products.

The co-expression of multiple antimicrobial peptides (AMPs) in genetically modified (GM) crops can give plants a broader antibacterial spectrum and lower the pathogen risk of drug resistance. Therefore, four penaeidins (shrimp-derived AMPs) were fused and encoded in an artificial gene (PEN1234), driven by the seed-specific promoter Pzein, with the aim of co-expression in seeds of transgenic rice. The resistant rice plants, acquired via Agrobacterium-mediated transformation and glufosinate screening, were identified by PCR and the modified disk-diffusion method, and eight GM lines with high AMP content in the seeds were obtained. Among them, the PenOs017 line had the largest penaeidin content, at approximately 251-300μg/g in seeds and 15-47μg/g in roots and leaves. The AMPs in the seeds kept their antibacterial properties even after the seed had been boiled in hot water and could significantly inhibit the growth of methicillin-resistant Staphylococcus aureus, and AMPs in the leaves could effectively inhibit Xanthomonas oryzae pv. Oryzae. The results indicate that PenOs017 seeds containing AMPs are an ideal raw-material candidate for antibiotic-free food and feed, and may require fewer petrochemical fungicides or bactericides for disease control during cultivation than conventional rice.

Induction of systemic resistance in rice plants against Burkholderia glumae infection by bioformulation of Streptomyces spp. under greenhouse conditions

The ability of plant growth-promoting Streptomyces (PGPS) against bacterial panicle blight (BPB) disease caused by Burkholderia glumae has been previously examined under laboratory and greenhouse conditions. To further harness their potential, the development of bioformulations containing PGPS is needed. This study investigates the efficacy of Streptomyces bioformulations in suppressing the growth of B. glumae under greenhouse conditions. The powder-based bioformulations of Streptomyces were prepared and characterized based on potential phytotoxic effect and shelf life stability. The efficacy of Streptomyces bioformulations in suppressing BPB disease was assessed according to the expression of Gns1 (β-1,3-glucanase), OsPR1a (pathogenesis-related class 1), Oswrky45 (SA-responsive) and OsJAMYB (JA-responsive) using RT-qPCR. The talc-kaolin-Streptomyces bioformulations (BioSTKR8, BioSJAS2 and BioSTBS5 containing Streptomyces corchorusii TKR8, Streptomyces corchorusii JAS2 and Streptomyces misionensis TBS5, respectively) showed no phytotoxic effect on rice plants. Bioformulations were more stable when stored under refrigeration than at room temperature, with more than 50 % spore viability at 180 days after storage. Treatment with BioSTKR8 (7 %) and BioSTBS5 (10 %) was able to reduce BPB disease severity while increasing rice yield by up to 301 % (BioSTKR8) and 170 % (BioSTBS5) relative to control (100 %). Transcript levels of Gns1, OsPR1a, Oswrky45 and OsJAMYB were up-regulated by the treatment of BioSTKR8 and BioSTBS5 at 7 DPI compared to the control. Results suggest that BioSTKR8 and BioSTBS5 are very promising bioformulations to be utilized as potential plant growth promoters and biological control agents (BCA) for sustainable rice production and BPB disease management.

Antagonistic activity and application of Bacillus velezensis strain Bv-303 against rice bacterial-blight disease caused by Xanthomonas oryzae pv. oryzae

In this study, a new Bacillus velezensis strain Bv-303 was identified and its biocontrol effect against rice bacterial-blight (BB) disease caused by Xanthomonas oryzae pv. oryzae (Xoo) was investigated. Cell-free supernatant (CFS) of strain Bv-303 under different growth conditions were prepared to test the antagonistic activity and stability against Xoo by the Oxford-cup method in vitro. The antibacterial effect of strain Bv-303 to BB disease in rice were further analyzed in vivo by spraying the cell-culture broth (CCB), CFS and cell-suspension water (CSW), respectively, on the rice leaves inoculated with Xoo. Additionally, rice seeds germination rate and seedling growth under the strain Bv-303 CCB treatment were tested. The results showed that the strain Bv-303 CFS significantly inhibited Xoo growth by 85.7%‒88.0% in vitro, which was also stable under extreme environment conditions such as heat, acid, alkali and ultraviolet light. As tested in vivo, spraying the CCB, CFS or CSW of strain Bv-303 on the Xoo-infected leaves enhanced rice plant resistance to BB disease, with CCB showing the highest increase (62.7%) in disease-resistance. Notably, CCB does not have negative effects on rice seed germination and seedling growth. Therefore, strain Bv-303 has great potential for biocontrol of the rice BB disease.

Proline Content, Physiological and Agronomic Characters of Rice (Oryza sativa cv. Inpari Unsoed 79 Agritan) under Treated with PGPR in Saline Medium

Tidal areas near the coastline are prone to salinity impacts as a negative impact of seawater intrusion which causes dissolved salt levels to increase. The biological approach using PGPR is an environmentally friendly approach. The aim of the study was to examine the effectiveness of useful bacteria from saline soils to increase the resistance of rice plants to salinity stress. The research was carried out from April to October 2022 in the Lab. Agronomy & Horticulture Faperta UNSOED. This research was experimental research using liquid culture techniques for cultivating plants using AB Mix media. The design used was a randomized block design with three replications. The treatments were included Control (P0), Acinetobacter junii (P1), Bacillus tropicus (P2), Acinetobacter schindleri (P3), Pseudomonas stutzeri (P4), Bacillus altitudinis (P5), Bacillus cereus (P6), dan Bacillus subtilis (P7). The results of the study showed that Diazotrophic Bacteria inoculation can increase the resistance of rice plants to rice plants by increasing proline production, increasing net assimilation rates and relative growth rates. Acinetobacter schindleri, Bacillus subtilis and Bacillus tropicus are potential N2 fixing bacterial strains to increase the growth and yield of rice under saline conditions. Treatment of Acinetobacter schindleri was able to provide the highest grain yields reaching 16.95 g/plant.

Lodging resistance of rice plants studied from the perspective of culm mechanical properties, carbon framework, free volume, and chemical composition

In this study, four varieties of rice were cultivated on the same farmland under same conditions and for same duration. However, their lodging resistance was found to be obviously different from each other. Herein, three key factors that highly influenced the lodging resistance were identified. First, in terms of morphological trait, in contrast to the generally believed theory that the overall thickness of the fresh culm wall governs the strength, the thickness of the depressed region of the dried basal culm wall largely determined the mechanical properties by acting as the weak link. This depressed region represents the vulnerable part with high syneresis rate. Second, the culm and its carbon framework exhibited sufficient strength and rigidity for both support and stability of the rice stem. The constraint of high lodging resistance of rice plants is attributed to the culm flexibility. Furthermore, the results of the positron annihilation lifetime spectroscopy corroborate that the most amorphous part and the highest-fraction free volume in the culm carbon framework were found for samples that exhibited high lodging resistance. This result confirmed the significant influence of the culm flexibility on lodging resistance. Third, a higher level of nitrogen element content in the basal culm can benefit its growth and development, which may contribute to an increase in lodging resistance of rice plants.

Discovery of rosin-based acylhydrazone derivatives as potential antifungal agents against rice Rhizoctonia solani for sustainable crop protection.

The use of fungicides to protect crops from diseases is an effective method, and novel environmentally friendly plant-derived fungicides with enhanced performance and low toxicity are urgent requirements for sustainable agriculture. Two kinds of rosin-based acylhydrazone compounds were designed and prepared. Based on the antifungal activity assessment against Rhizoctonia solani, Fusarium oxysporum, Phytophthora capsici, Sclerotinia sclerotiorum, and Botrytis cinerea, acylhydrazone derivatives containing a thiophene ring were screened and showed an inhibitory effect on rice R. solani. Among them, Compound 4n, with an electron-withdrawing group on the benzene ring structure attached to the thiophene ring, showed optimal activity, and the EC50 value was 0.981 mg L-1 , which was lower than that of carbendazim. Furthermore, it was indicated that 4n could affect the mycelial morphology, cell membrane permeability and microstructure, cause the generation of reactive oxygen species in fungal cells, and damage the nucleus and mitochondrial physiological function, resulting in the cell death of R. solani. Meanwhile, Compound 4n exhibited a better therapeutic effect on in vivo rice plants. However, the induction activity of 4n on the defense enzyme in rice leaf sheaths showed that 4n stimulates the initial resistance of rice plants by removing active oxygen, thereby protecting the cell membrane or enhancing the strength of the cell wall. Through the quantitative structure-activity relationship study, the quantitative chemical and electrostatic descriptors significantly affect the binding of 4n with the receptor, which improves its antifungal activity. This study provides a basis for exploiting potential rosin-based fungicides in promoting sustainable crop protection. © 2022 Society of Chemical Industry.

The Homeodomain-Leucine Zipper Genes Family Regulates the Jinggangmycin Mediated Immune Response of Oryza sativa to Nilaparvata lugens, and Laodelphax striatellus

The homeodomain-leucine zipper (HDZIP) is an important transcription factor family, instrumental not only in growth but in finetuning plant responses to environmental adversaries. Despite the plethora of literature available, the role of HDZIP genes under chewing and sucking insects remains elusive. Herein, we identified 40 OsHDZIP genes from the rice genome database. The evolutionary relationship, gene structure, conserved motifs, and chemical properties highlight the key aspects of OsHDZIP genes in rice. The OsHDZIP family is divided into a further four subfamilies (i.e., HDZIP I, HDZIP II, HDZIP III, and HDZIP IV). Moreover, the protein–protein interaction and Gene Ontology (GO) analysis showed that OsHDZIP genes regulate plant growth and response to various environmental stimuli. Various microRNA (miRNA) families targeted HDZIP III subfamily genes. The microarray data analysis showed that OsHDZIP was expressed in almost all tested tissues. Additionally, the differential expression patterns of the OsHDZIP genes were found under salinity stress and hormonal treatments, whereas under brown planthopper (BPH), striped stem borer (SSB), and rice leaf folder (RLF), only OsHDZIP3, OsHDZIP4, OsHDZIP40, OsHDZIP10, and OsHDZIP20 displayed expression. The qRT-PCR analysis further validated the expression of OsHDZIP20, OsHDZIP40, and OsHDZIP10 under BPH, small brown planthopper (SBPH) infestations, and jinggangmycin (JGM) spraying applications. Our results provide detailed knowledge of the OsHDZIP gene family resistance in rice plants and will facilitate the development of stress-resilient cultivars, particularly against chewing and sucking insect pests.

Seaweed Oligosaccharide Synergistic Silicate Improves the Resistance of Rice Plants to Lodging Stress under High Nitrogen Level

The objective of this study was to determine the effect of seaweed oligosaccharide synergistic silicate (Si) fertilizer (SOSSiF) on rice resistance to lodging stress. The results showed that a spraying SOSSiF decreased apparent lodging index and enhanced rice yield significantly under a high N level. The spraying test indicated that the apparent lodging rate of rice was the lowest when SOSSiF was sprayed for four times, and the dosage was 45 kg/ha each time. Morphological and anatomical analysis indicated that SOSSiF decreased plant height and the lower internode length of ZCSM and increased culm cross-sectional area and wall thickness of JNSM significantly compared with the control. Furthermore, SOSSiF enhanced bending strength of rice culm by 38.8% to 63.6%, and reduced lodging index by 36.8% to 42.6%. Chemical component analysis found that SOSSiF elevated the contents of soluble sugar, cellulose, Si, and lignin in the culms of ZCSM and JNSM. Correlation analysis revealed that the lodging index was positively correlated with the length of the lower internode, and was negatively correlated with culm bending strength and culm thickness. The above results suggested that spraying SOSSiF elevates culm contents of Si and lignin and enhances bending strength, thus improving rice lodging resistance and production.

A secreted fungal subtilase interferes with rice immunity via degradation of SUPPRESSOR OF G2 ALLELE OF skp1.

Serine protease subtilase, found widely in both eukaryotes and prokaryotes, participates in various biological processes. However, how fungal subtilase regulates plant immunity is a major concern. Here, we identified a secreted fungal subtilase, UvPr1a, from the rice false smut (RFS) fungus Ustilaginoidea virens. We characterized UvPr1a as a virulence effector localized to the plant cytoplasm that inhibits plant cell death induced by Bax. Heterologous expression of UvPr1a in rice (Oryza sativa) enhanced plant susceptibility to rice pathogens. UvPr1a interacted with the important rice protein SUPPRESSOR OF G2 ALLELE OF skp1 (OsSGT1), a positive regulator of innate immunity against multiple rice pathogens, degrading OsSGT1 in a protease activity-dependent manner. Furthermore, host-induced gene silencing of UvPr1a compromised disease resistance of rice plants. Our work reveals a previously uncharacterized fungal virulence strategy in which a fungal pathogen secretes a subtilase to interfere with rice immunity through degradation of OsSGT1, thereby promoting infection. These genetic resources provide tools for introducing RFS resistance and further our understanding of plant-pathogen interactions.

Comprehensive Bioinformatics and Expression Analysis of the TLP Gene Family Revealed Its Role in Regulating the Response of Oryza sativa to Nilaparvata lugens, Laodelphax striatellus, and Jinggangmycin

Thaumatin-like proteins (TLPs), which belong to pathogenesis-related (PR) protein family 5 (PR5), are involved in the plant host defense and developmental processes. Detailed information regarding the TLP gene family in rice remains elusive. Here, we identified 43 OsTLP genes from the rice genome database. The in silico analysis comprised of the evolutionary tree, gene structure, conserved motifs, and chemical properties highlighted the key aspects of the OsTLP genes. By phylogenetic analysis, the OsTLP genes were classified into ten groups (OsTLPI-OsTLPX). Gene ontology (GO) analysis showed that OsTLP genes regulate plant growth and response to various environmental stimuli. Moreover, most of the OsTLP genes are expressed in almost all tissues. Microarray data showed differential expression trends of OsTLP genes under salinity stress and hormonal treatments, whereas under BPH, SSB, and RFL, only OsTLP1, OsTLP2 and OsTLP27 were expressed. The qRT-PCR analysis showed OsTLP27 as the prominent gene, displayed by its upregulated expression under JGM. Our results provide detailed knowledge of OsTLP gene resistance in rice plants, and we believe the current study will facilitate the development of cultivars resistant to biotic/abiotic stress, particularly stress caused by the chewing and sucking of insect pests.

ECOFRIENDLY APPLICATIONS OF PLANT HORMONES TO ENHANCE RICE RESISTANCE AGAINST BROWN SPOT OF RICE DISEASE

The plant hormones application increased the resistance in rice plants against brown leaf spot disease. That’s, why, the effect of five plant hormones (salicylic acid, citric Acid, K2HPO4, KH2PO4, benzoic acid) on the resistance of rice plants (Oryzae sativa L.) to brown leaf spot disease cause by Bipolaris oryzae were evaluated in field. The results showed that all of the plant hormones evaluated distinctly increased resistance of rice to BLS disease. All plant hormones employed at three concentrations (0.5, 0.75 and 1%), significantly decreased the incidence of brown leaf spot. Salicylic Acid exhibited minimum disease incidence (%) as compared to benzoic acid, K2HPO4, KH2PO4, and citric acid under greenhouse and field condition as compared to control. Interaction between treatments and concentration (T×C) expressed that salicylic acid expressed minimum disease incidence at 0.05% (22.52), 0.75% (19.92) and 1.0% (17.32) %, followed by benzoic acid (27.26,25.23,22.92), K2HPO4 (28.78,25.72,22.83), KH2PO4 (32.61,29.94,27.62) and citric acid (36.96,34.27,31.55) % respectively in field condition. These results recommended that plant hormones have key role in controlling the brown leaf spot disease through inducing resistance in rice plants.