Expression Analysis Reveals Differentially Expressed Genes in BPH and WBPH Associated with Resistance in Rice RILs Derived from a Cross between RP2068 and TN1.

BPH (brown planthopper) and WBPH (white backed planthopper) are significant rice pests that often co-occur as sympatric species and cause substantial yield loss. Despite their genetic similarities, different host-resistance genes confer resistance against these two hoppers. The defense mechanisms in rice against these pests are complex, and the molecular processes regulating their responses remain largely unknown.

Field and agroinoculation screening of national collection of urd bean () germplasm accessions for new sources of (MYMV) resistance.

Yellow mosaic disease (YMD) is a major problem in Urd bean ( L.) in India, which causes huge yield losses. Breeding for wide spectrum and durable (MYMV) resistance and cultivating resistant cultivars is the most appropriate and effective approach.

Infestation of Rice by Gall Midge Influences Density and Diversity of and in the Host Plant Microbiome.

The virulence of phytophagous insects is predominantly determined by their ability to evade or suppress host defense for their survival. The rice gall midge (GM, ), a monophagous pest of rice, elicits a host defense similar to the one elicited upon pathogen attack. This could be due to the GM feeding behaviour, wherein the GM endosymbionts are transferred to the host plant oral secretions, and as a result, the host mounts an appropriate defense response(s) (.

Polymorphisms in the hypervariable control region of the mitochondrial DNA differentiate BPH populations.

The brown planthopper (BPH; ) is one of India's most destructive pests of rice. BPH, a monophagous migratory insect, reported from all major rice-growing ecosystems of the country, is capable of traversing large distances and causing massive crop loss. A crucial step for developing viable management strategies is understanding its population dynamics.

RNA-Sequencing Reveals Differentially Expressed Rice Genes Functionally Associated with Defense against BPH and WBPH in RILs Derived from a Cross between RP2068 and TN1.

Background: Rice is staple food for over two billion people. Planthoppers like BPH and WBPH occur together in most of rice growing regions across Asia and cause extensive yield loss by feeding and transmission of disease-causing viruses. Chemical control of the pest is expensive and ecologically disastrous; breeding resistant varieties is an acceptable option.

Map-based cloning and validation of a gall midge resistance gene, Gm8, encoding a proline-rich protein in the rice variety Aganni.

The Asian rice gall midge (ARGM), Orseolia oryzae is an important insect pest causing an annual yield loss of about US$ 80 million in India. Till now 11 R genes and seven biotypes of the pest have been characterized and reported. The indica rice variety Aganni, a landrace from the state of Kerala, is known to carry the gall midge resistance gene Gm8 with HR-type of resistance.

Expression Profile of Defense Genes in Rice Lines Pyramided with Resistance Genes Against Bacterial Blight, Fungal Blast and Insect Gall Midge.

Background: Rice, a major food crop of the world, endures many major biotic stresses like bacterial blight (BB), fungal blast (BL) and the insect Asian rice gall midge (GM) that cause significant yield losses. Progress in tagging, mapping and cloning of several resistance (R) genes against aforesaid stresses has led to marker assisted multigene introgression into elite cultivars for multiple and durable resistance. However, no detailed study has been made on possible interactions among these genes when expressed simultaneously under combined stresses.

Bacterial Community Structure in the Asian Rice Gall Midge Reveals a Varied Microbiome Rich in Proteobacteria.

The Asian rice gall midge (ARGM) has emerged as a model gall forming pest of rice. The ARGM infestation of rice results in failure of panicle formation and economic loss. Understanding the molecular basis of ARGM-rice interactions is very crucial in order to control this devastating pest of rice.

Genomics of the Asian rice gall midge and its interactions with rice.

Understanding virulence and manipulative strategies of gall formers will reveal new facets of plant defense and insect counter defense. Among the gall midges, the Asian rice gall midge (AGM) has emerged as a model for studies on plant-insect interactions. Data from several genomics, transcriptomics and metabolomics studies have revealed diverse strategies adopted by AGM to successfully invade the host while overcoming its defense.

Geographic and Research Center Origins of Rice Resistance to Asian Planthoppers and Leafhoppers: Implications for Rice Breeding and Gene Deployment.

This study examines aspects of virulence to resistant rice varieties among planthoppers and leafhoppers. Using a series of resistant varieties, brown planthopper, , virulence was assessed in seedlings and early-tillering plants at seven research centers in South and East Asia. Virulence of the whitebacked planthopper, , in Taiwan and the Philippines was also assessed.

Metabolic and transcriptomic changes induced in host during hypersensitive response mediated resistance in rice against the Asian rice gall midge.

Background: An incompatible interaction between rice (Oryza sativa) and the Asian rice gall midge (AGM, Orseolia oryzae Wood-Mason), that is usually manifested through a hypersensitive response (HR), represents an intricate relationship between the resistant host and its avirulent pest. We investigated changes in the transcriptome and metabolome of the host (indica rice variety: RP2068-18-3-5, RP), showing HR when attacked by an avirulent gall midge biotype (GMB1), to deduce molecular and biochemical bases of such a complex interaction. Till now, such an integrated analysis of host transcriptome and metabolome has not been reported for any rice-insect interaction.

Analysis of SSH library of rice variety Aganni reveals candidate gall midge resistance genes.

The Asian rice gall midge, Orseolia oryzae, is a serious insect pest causing extensive yield loss. Interaction between the gall midge and rice genotypes is known to be on a gene-for-gene basis. Here, we report molecular basis of HR- (hypersensitive reaction-negative) type of resistance in Aganni (an indica rice variety possessing gall midge resistance gene Gm8) through the construction and analysis of a suppressive subtraction hybridization (SSH) cDNA library.

Rice-gall midge interactions: Battle for survival.

Gall midges are insects specialized in maneuvering plant growth, metabolic and defense pathways for their benefit. The Asian rice gall midge and rice share such an intimate relationship that there is a constant battle for survival by either partner. Diverse responses by the rice host against the midge include necrotic hypersensitive resistance reaction, non-hypersensitive resistance reaction and gall-forming compatible interaction.

Feeding on resistant rice leads to enhanced expression of defender against apoptotic cell death (OoDAD1) in the Asian rice gall midge.

Background: The Asian rice gall midge (Orseolia oryzae) is a destructive insect pest of rice. Gall midge infestation in rice triggers either compatible or incompatible interactions leading to survival or mortality of the feeding maggots, respectively. In incompatible interactions, generation of plant allelochemicals/defense molecules and/or inability of the maggots to continue feeding on the host initiate(s) apoptosis within the maggots.

The Asian Rice Gall Midge (Orseolia oryzae) Mitogenome Has Evolved Novel Gene Boundaries and Tandem Repeats That Distinguish Its Biotypes.

The complete mitochondrial genome of the Asian rice gall midge, Orseolia oryzae (Diptera; Cecidomyiidae) was sequenced, annotated and analysed in the present study. The circular genome is 15,286 bp with 13 protein-coding genes, 22 tRNAs and 2 ribosomal RNA genes, and a 578 bp non-coding control region. All protein coding genes used conventional start codons and terminated with a complete stop codon.

Gas chromatography mass spectrometry based metabolic profiling reveals biomarkers involved in rice-gall midge interactions.

The Asian rice gall midge (Orseolia oryzae Wood-Mason) is a serious pest of rice that causes huge loss in yield. While feeding inside the susceptible host, maggots secrete substances that facilitate the formation of a hollow tube-like structure called gall and prevent panicle formation. The present investigation was carried out to get an account of biochemical changes occurring in the rice plant upon gall midge feeding.

A putative candidate for the recessive gall midge resistance gene gm3 in rice identified and validated.

We report here tagging and fine-mapping of gm3 gene, development of a functional marker for it and its use in marker-assisted selection. The recessive rice gall midge resistance gene, gm3 identified in the rice breeding line RP2068-18-3-5 confers resistance against five of the seven Indian biotypes of the Asian rice gall midge Orseolia oryzae. We report here tagging and fine-mapping of gm3 gene, development of a functional marker for it and demonstrated its use in marker-assisted selection (MAS).

Suppressive subtraction hybridization reveals that rice gall midge attack elicits plant-pathogen-like responses in rice.

The Asian rice gall midge, Orseolia oryzae (Diptera: Cecidomyiidae), is the third most destructive insect pest of rice (Oryza sativa L.). Till date, 11 gall midge resistance gene loci have been characterized in different rice varieties.

Pyrosequencing-based transcriptome analysis of the asian rice gall midge reveals differential response during compatible and incompatible interaction.

The Asian rice gall midge (Orseolia oryzae) is a major pest responsible for immense loss in rice productivity. Currently, very little knowledge exists with regard to this insect at the molecular level. The present study was initiated with the aim of developing molecular resources as well as identifying alterations at the transcriptome level in the gall midge maggots that are in a compatible (SH) or in an incompatible interaction (RH) with their rice host.

Differential gene expression in gall midge susceptible rice genotypes revealed by suppressive subtraction hybridization (SSH) cDNA libraries and microarray analysis.

Background: A major pest of rice, the Asian rice gall midge (Orseolia oryzae Wood-Mason), causes significant yield losses in the rice growing regions throughout Asia. Feeding by the larvae induces susceptible plants to produce nutritive tissue to support growth and development. In order to identify molecular signatures during compatible interactions, genome wide transcriptional profiling was performed using SSH library and microarray technology.

Expression of Orseolia oryzae nucleoside diphosphate kinase (OoNDPK) is enhanced in rice gall midge feeding on susceptible rice hosts and its over-expression leads to salt tolerance in Escherichia coli.

The Asian rice gall midge, Orseolia oryzae, is a major dipteran pest of rice, with many known biotypes. The present investigation was initiated to understand the molecular mechanisms of infestation for developing novel integrated pest management strategies. We isolated and characterized a gene, nucleoside diphosphate kinase (OoNDPK), from the rice gall midge, encoding a protein with 169 amino acid residues and with a secretory signal sequence - an observation that assumes significance as salivary gland secretions have been implicated to play a major role in insect-plant interactions.

A novel mechanism of gall midge resistance in the rice variety Kavya revealed by microarray analysis.

The Asian rice gall midge [Orseolia oryzae (Wood-Mason)] is an important rice pest causing an annual average yield loss of about US $80 million in India. Rice varieties possess several discrete resistance (R) genes conferring resistance against the pest in two distinct ways, i.e.

Bt rice evaluation and deployment strategies.

Bacillus thuringiensis (Bt), a gram positive soil bacteria was first identified and named by Japanese microbiologist Shigetane Ishiwata in 1901. During sporulation Bt produces proteinaceous parasporal crystal proteins called δ-endotoxins, or Cry proteins, which are insecticidal. Numerous Cry proteins have been isolated and characterized from different Bt strains with activity against insects, mites and nematodes.

Serine proteases-like genes in the asian rice gall midge show differential expression in compatible and incompatible interactions with rice.

The Asian rice gall midge, Orseolia oryzae (Wood-Mason), is a serious pest of rice. Investigations into the gall midge-rice interaction will unveil the underlying molecular mechanisms which, in turn, can be used as a tool to assist in developing suitable integrated pest management strategies. The insect gut is known to be involved in various physiological and biological processes including digestion, detoxification and interaction with the host.

Compatible interaction with its rice host leads to enhanced expression of the gamma subunit of oligosaccharyl transferase in the Asian rice gall midge, Orseolia oryzae.

The Asian rice gall midge, Orseolia oryzae, is a fast evolving, damaging pest of rice. Understanding the underlying molecular mechanism of interaction between the gall midge and rice will help in devising strategies to control and manage the pest. The present study aims to identify rice-responsive genes in the gall midge that aid pest survival.