RESUMEN
BACKGROUND: Citrus huanglongbing (HLB) is a devastating disease caused by Candidatus Liberibacter asiaticus (CLas) that affects the citrus industry. In nature, CLas relies primarily on Diaphorina citri Kuwayama as its vector for dissemination. After D. citri ingests CLas-infected citrus, the pathogen infiltrates the insect's body, where it thrives, reproduces, and exerts regulatory control over the growth and metabolism of D. citri. Previous studies have shown that CLas alters the composition of proteins in the saliva of D. citri, but the functions of these proteins remain largely unknown. RESULTS: In this study, we detected two proteins (DcitSGP1 and DcitSGP3) with high expression levels in CLas-infected D. citri. Quantitative PCR and Western blotting analysis showed that the two proteins were highly expressed in the salivary glands and delivered into the host plant during feeding. Silencing the two genes significantly decreased the survival rate for D. citri, reduced phloem nutrition sucking and promoted jasmonic acid (JA) defenses in citrus. By contrast, after overexpressing the two genes in citrus, the expression levels of JA pathway-associated genes decreased. CONCLUSION: Our results suggest that CLas can indirectly suppress the defenses of citrus and support feeding by D. citri via increasing the levels of effectors in the insect's saliva. This discovery facilitates further research into the interaction between insect vectors and pathogens. © 2024 Society of Chemical Industry.
RESUMEN
<p><b>OBJECTIVE</b>To investigate the effect of silencing NSD2 gene by RNA interference on the proliferation, apoptosis and the alteration of Akt /mTOR signaling pathway in diffuse large B cell lymphoma OCI-Ly3 cells.</p><p><b>METHODS</b>The shRNA targeting NSD2 gene was transfected into OCI-Ly3 cells by lentivirus infection. The NSD2 mRNA and protein were detected by real time Q-PCR and Western blot, respectively. The cell proliferation was detected by CCK-8 and apoptosis was measured by flow cytometry. The expressions of BCL-2, BAX, caspase-3, Akt, p-Akt, p-mTOR, p-P70S6K, H3K36me2 were detected by Western blot.</p><p><b>RESULTS</b>After transfecting the OCI-Ly3 cells by NSD2-shRNA for 72 h, the expressions of NSD2 mRNA and protein both were down-regulated(P<0.05), the proliferation rate of cells in NSD2 shRNA group was significantly lower than that in control and Neg shRNA groups (P<0.05); the apoptosis rate of cells in NSD2 shRNA group was significantly higher than that in control and neg-shRNA group (30.37±4.22)% vs 1.36±0.52 % and 2.17±1.43)%(P<0.05); the expressions of BAX and caspase-3 were up-regulated, while the expression of BCL-2 was down-regulated; the H3K36me2 level significantly decreased as compared with control group, no obvious decrease of the total protein level of AKT was found, but the expressions of p-Akt, p-mTOR and p-70S6K were down-regulated.</p><p><b>CONCLUSION</b>The silencing NSD2 gene can inhibit the proliferation and induce the apoptosis of OCI-Ly3 cells, their mechanisms may relate with regulating the H3K36me2 level, specifically inhibiting the activivty of AKT/mTOR signal pathway.</p>
