Dual-Action Pesticide Carrier That Continuously Induces Plant Resistance, Enhances Plant Anti-Tobacco Mosaic Virus Activity, and Promotes Plant Growth.

Improving plant resistance against systemic diseases remains a challenging research topic. In this study, we developed a dual-action pesticide-loaded hydrogel with the capacity to significantly induce plant resistance against tobacco mosaic virus (TMV) infection and promote plant growth. We produced an alginate-lentinan-amino-oligosaccharide hydrogel (ALA-hydrogel) by coating the surface of an alginate-lentinan drug-loaded hydrogel (AL-hydrogel) with amino-oligosaccharide using electrostatic action. We determined the formation of the amino-oligosaccharide film using various approaches, including Fourier transform infrared spectrometry, the ζ potential test, scanning electron microscopy, and elemental analysis. It was found that the ALA-hydrogel exhibited stable sustained-release activity, and the release time was significantly longer than that of the AL-hydrogel. In addition, we demonstrated that the ALA-hydrogel was able to continuously and strongly induce plant resistance against TMV and increase the release of calcium ions to promote Nicotiana benthamiana growth. Meanwhile, the ALA-hydrogel maintained an extremely high safety to organisms. Our findings provide an alternative to the traditional approach of applying pesticide for controlling plant viral diseases. In the future, this hydrogel with the simple synthesis method, green synthetic materials, and its efficiency in the induction of plant resistance will attract increasing attention and have good potential to be employed in plant protection and agricultural production.

Cellulose Nanocrystal Surface Cationization: A New Fungicide with High Activity against Phycomycetes capsici.

At present, the management of Phytophthora capsici (P. capsici) mainly relies on chemical pesticides. However, along with the resistance generated by P. capsici to these chemical pesticides, the toxicity and non-degradability of this chemical molecule may also cause serious environmental problems. Herein, a new bio-based nano-antifungal material (CNC@CTAB) was made with coating hexadecyl trimethyl ammonium bromide (CTAB) on the surface of a cellulose nanocrystal (CNC). This material was then applied to the prevention of P. capcisi. This particle was facilely fabricated by mixing CTAB and sulfuric group modified CNC in an aqueous solvent. Compared to pure CTAB, the enrichment of CTAB on the CNC surface showed a better anti-oomycete activity both in vitro and in vivo. When CNC@CTAB was applied on P. capsici in vitro, the inhibition rate reached as high as 100%, while on the pepper leaf, the particle could also efficiently prevent the infection of P. capsici, and achieve a disease index as low as zero Thus, considering the high safety of CNC@CTAB in agricultural applications, and its high anti-oomycete activity against P. capsici, we believe that this CNC@CTAB has great application potential as a new green nano-fungicide in P. capsici management during the production of peppers or other vegetables.