Control of plant virus diseases largely depends on the induced plant defense achieved by the external application of synthetic chemical inducers with the ability to modify defense-signaling pathways. However, most of the molecular mechanisms underlying these chemical inducers remain unknown. Here, we developed a lentinan-loaded hydrogel with a core-shell structure and discovered how it protects plants from different virus infections. The hydrogel was synthesized by adding a chitosan shell on the surface of the polyanion sodium alginate-Ca 2+-lentinan (LNT) hydrogel (SL-gel) to form a CSL-gel. CSL-gels exhibit the capacity to prolong the stable release of lentinan and promote Ca 2+ release. Application of CSL-gels on the root of plants induces broad-spectrum resistance against TMV, TRV, PVX and TuMV). RNA-seq analysis identified that the calmodulin-like protein 19 gene ( NbCML19) is upregulated by the sustained release of Ca 2+ from the CSL-gel, and silencing and overexpression of NbCML19 alter the susceptibility and resistance of tobacco to TMV. Our findings provide evidence that this novel and synthetic CSL-gel strongly inhibits the infection of plant viruses by the sustainable release of LNT and Ca 2+. This study uncovers a novel mode of action by which CSL-gels trigger NbCML19 expression through the stable and sustained release of Ca 2+.

Control of plant virus diseases largely depends on the induced plant defense achieved by the external application of synthetic chemical inducers with the ability to modify defense-signaling pathways. However, most of the molecular mechanisms underlying these chemical inducers remain unknown. Here, we developed a lentinan-loaded hydrogel with a core-shell structure and discovered how it protects plants from different virus infections. The hydrogel was synthesized by adding a chitosan shell on the surface of the polyanion sodium alginate-Ca2+-lentinan (LNT) hydrogel (SL-gel) to form a CSL-gel. CSL-gels exhibit the capacity to prolong the stable release of lentinan and promote Ca2+ release. Application of CSL-gels on the root of plants induces broad-spectrum resistance against TMV, TRV, PVX and TuMV). RNA-seq analysis identified that the calmodulin-like protein 19 gene (CML19) is upregulated by the sustained release of Ca2+ from the CSL-gel, and silencing and overexpression of CML19 alter the susceptibility and resistance of tobacco to TMV. Our findings provide evidence that this novel and synthetic CSL-gel strongly inhibits the infection of plant viruses by the sustainable release of LNT and Ca2+. This study uncovers a novel mode of action by which CSL-gels trigger CML19 expression through the stable and sustained release of Ca2+.

Control of plant virus disease largely depends on the induced plant defense achieved by the external application of synthetic chemical inducers with the ability to modify defense-signaling pathways. However, most of the molecular mechanisms underlying these chemical inducers remain unknown. Here, we developed a lentinan-loaded hy-drogel with a core-shell structure and discovered how it protects plants from different virus infections. The hydrogel was synthesized by adding a chitosan shell on the sur-face of the polyanion sodium alginate-calcium ion-lentinan (LNT) hydrogel (SL-gel) to form CSL-gel. CSL-gel exhibits the capacity to prolong the stable release of lenti-nan and promote calcium ions release. Application of CSL-gel on the root of plants induces broad-spectrum resistance against TMV, TuMV, PVX and TRV. Further-more, RNA-seq analysis identified that the calmodulin-like protein 19 gene (CML19) is upregulated by the sustained release of calcium ions from the CSL-gel, and silenc-ing and overexpression of CML19 alter the susceptibility and resistance of tobacco to TMV. Our findings provide evidence that the novel and synthetic CSL-gel with the sustainable release of LNT and calcium ion strongly inhibits the plant virus infection. This study uncovers a novel mode of action by which CSL-gel with the stable release of calcium ion triggers CML19 expression.

Control of plant virus disease largely depends on the induced plant defense achieved by the external application of synthetic chemical inducers with the ability to modify defense-signaling pathways. However, most of the molecular mechanisms underlying these inducers remain unknown. Here, we developed a lentinan-loaded hydrogel with the core-shell structure and discovered how it protects plant from different virus infections. The hydrogel was synthesized by adding a chitosan shell on the surface of the sodium alginate-calcium ion-lentinan (LNT) hydrogel (SL-gel) to form CSL-gel. CSL-gel exhibits the capacity of prolonging the stable-release of lentinan and promoting calcium ions release. Application of CSL-gel on the root of plants significantly promotes plant growth and development and induces broad-spectrum resistance against TMV, TuMV, PVX and TRV. Furthermore, we found that the sustained release of calcium ions from the CSL-gel triggers the high expression of cal-modulin-like protein 30 (CML30), and silencing of CML30 enhances the susceptibility of tobacco to TMV. Our findings provide evidence that the novel and synthetic CSL-gel with the sustainable release of LNT and calcium ion strongly inhibits the plant virus infection. This study uncovers a novel mode of action by which CSL-gel with the stable release of calcium ion triggers CML30 expression.