A small RNA effector conserved in herbivore insects suppresses host plant defense by cross-kingdom gene silencing.

Herbivore insects deploy salivary effectors to manipulate the defense of their host plants. However, it remains unclear whether small RNAs from insects function as effectors in regulating plant-insect interactions. Here, we report that a microRNA (miR29-b) found in the saliva of phloem-feeding whitefly (Bemisa tabaci) can transfer into the host plant phloem during feeding and fine-tune the defense response of tobacco (Nicotiana tabacum).

The SA-WRKY70-PR-Callose Axis Mediates Plant Defense Against Whitefly Eggs.

The molecular mechanisms of plant responses to phytophagous insect eggs are poorly understood, despite their importance in insect-plant interactions. This study investigates the plant defense mechanisms triggered by the eggs of whitefly , a globally significant agricultural pest. A transcriptome comparison of tobacco plants with and without eggs revealed that whitefly eggs may activate the response of defense-related genes, including those involved in the salicylic acid (SA) signaling pathway.

Using salicylic acid-responsive promoters to drive the expression of jasmonic acid-regulated genes enhances plant resistance to whiteflies.

Background: Jasmonic acid (JA) is an important phytohormone used to defend against herbivores, but it does not respond to whitefly feeding. Conversely, another phytohormone, salicylic acid (SA), is induced when plants are fed upon by whiteflies. JA has a better anti-whitefly effect than SA; however, there is limited research on how to effectively improve plant resistance by utilizing the different responses of these phytohormones to whitefly feeding.

Metabolic and Molecular Insights Into Nicotiana benthamiana Trichome Exudates: An Ammunition Depot for Plant Resistance Against Insect Pests.

Nicotiana benthamiana, a widely acknowledged laboratory model plant for molecular studies, exhibits lethality to certain insect pests and can serve as a dead-end trap plant for pest control in the field. However, the underlying mechanism of N. benthamiana's resistance against insects remains unknown.

DNA methylase 1 influences temperature responses and development in the invasive pest Tuta absoluta.

DNA methylase 1 (Dnmt1) is an important regulatory factor associated with biochemical signals required for insect development. It responds to changes in the environment and triggers phenotypic plasticity. Meanwhile, Tuta absoluta Meyrick (Lepidoptera: Gelechiidae)-a destructive invasive pest-can rapidly invade and adapt to different habitats; however, the role of Dnmt1 in this organism has not been elucidated.

Opsin mutants alter host plant selection by color vision in the nocturnal invasive pest Tuta absoluta.

In insects, vision is crucial in finding host plants, but its role in nocturnal insects is largely unknown. Vision involves responses to specific spectra of photon wavelengths and opsins plays an important role in this process. Long-wavelength sensitive opsin (LW opsin) and blue-sensitive opsin (BL opsin) are main visual opsin proteins and play important in behavior regulation.

Chromatin-Remodelling ATPases and Are Essential for Reproduction in the Destructive Pest .

The tomato leaf miner () is one of the top 20 plant pests worldwide. We cloned and identified the chromatin-remodelling ATPase genes and by RACE and bioinformatic analysis, respectively; used RT-qPCR to examine their expression patterns during different life cycle stages; and elucidated their roles in insect reproduction using double-stranded RNA injections. The full-length cDNA of was 3428 bp and it encoded a 1025-aa polypeptide.

Molecular Characterization of TRPA Subfamily Genes and Function in Temperature Preference in (Meyrick) (Lepidoptera: Gelechiidae).

To reveal the mechanism of temperature preference in , one of the top 20 plant pests in the world, we cloned and identified , , and genes by RACE and bioinformatic analysis, and clarified their expression profiles during different development stages using real-time PCR, and revealed their function in preference temperature by RNAi. The full-length cDNA of was 3136 bp, with a 2865-bp open reading frame encoding a 259.89-kDa protein; and the partial length cDNA of was 2326-bp, with a 2025-bp open reading frame encoding a 193.

Using RNA Interference to Reveal the Function of Chromatin Remodeling Factor ISWI in Temperature Tolerance in Middle East-Asia Minor 1 Cryptic Species.

Invasive species often encounter rapid environmental changes during invasions and only the individuals that successfully overcome environmental stresses can colonize and spread. Chromatin remodeling may be essential in environmental adaptation. To assess the functions of imitation switch (ISWI) in invasive Middle East-Asia Minor 1 (MEAM1) cryptic species, we cloned and characterized the MEAM1 gene and determined its functions in response to thermal stress.

Expression and purification of a recombinant antibacterial peptide, cecropin, from Escherichia coli.

Insect cecropins are small basic polypeptides synthesized in fat body and hemocytes in response to bacterial infections or hypodermic injuries. To explore a new approach for high expression of soluble cecropin in Escherichia coli cells, we fused the sequence encoding Musca domestica mature cecropin (named Mdmcec) in-frame to thioredoxin (TRX) gene to construct an expression vector pTRX-6His-Mdmcec. An enterokinase cleavage site was introduced between the 6xHis-tag and Mdmcec to facilitate final release of the recombinant Mdmcec.