Silica nanoparticles protect rice against biotic and abiotic stresses

Abstract

Background By 2050, the world population will increase to 10 billion which urged global demand for food production to double. Plant disease and land drought will make the situation more dire, and safer and environment-friendly materials are thus considered as a new countermeasure. The rice blast fungus, Magnaporthe oryzae, causes one of the most destructive diseases of cultivated rice worldwide that seriously threatens rice production. Unfortunately, traditional breeding nor chemical approaches along control it well. Nowadays, nanotechnology stands as a new weapon against these mounting challenges and silica nanoparticles (SiO2 NPs) have been considered as potential new safer agrochemicals recently but the systematically studies remain limited, especially in rice. Results Salicylic acid (SA) is a key plant hormone essential for establishing plant resistance to several pathogens and its further affected a special form of induced resistance, the systemic acquired resistance (SAR), which considered as an important aspect of plant innate immunity from the locally induced disease resistance to the whole plant. Here we showed that SiO2 NPs could stimulate plant immunity to protect rice against M. oryzae through foliar treatment that significantly decreased disease severity by nearly 70% within an appropriate concentration range. Excessive concentration of foliar treatment led to disordered intake and abnormal SA responsive genes expressions which weaken the plant resistance and even aggravated the disease. Importantly, this SA-dependent fungal resistance could achieve better results with root treatment through a SAR manner with no phytotoxicity since the orderly and moderate absorption. What’s more, root treatment with SiO2 NPs could also promote root development which was better to deal with drought. Conclusions Taken together, our findings not only revealed SiO2 NPs as a potential effective and safe strategy to protect rice against biotic and abiotic stresses, but also identify root treatment for the appropriate application method since it seems not causing negative effects and even have promotion on root development. Graphical Abstract

Silica nanoparticles promote wheat growth by mediating hormones and sugar metabolism

“…Si has been proven to play a favorable role in plant growth, mineral nutrition, mechanical strength, and resistance to fungal diseases [ 14 , 15 ]. To investigate the effect of nanoparticles on plants, the nanoparticles are usually prepared as suspensions and sprayed onto plants or by soaking the plants into suspension [ 7 , 16 , 17 ]. In this study, a SiNP200 suspension was prepared and sprayed onto the leaves.…”

“…Currently, Si fertilizer is mainly applied to the soil by adding silicon materials such as blast furnace slag, so as to improve the soil and promote plant growth [ 6 ]. In recent years, nanomaterials have been widely used in agriculture as growth stimulators, plant protection products, and nano-fertilizers [ 7 ]. Among these, silica nanoparticles (SiNPs) have gained increasing attention because of their unique properties, such as high pore volume, large surface area, low toxicity, high stability, controllable morphology, and ease of surface functionalization [ 8 ].…”

Combined Effects of Soil Silicon and Host Plant Resistance on Planthoppers, Blast and Bacterial Blight in Tropical Rice

“…Furthermore, in our experiments, although the effects of soil silicon were small compared to the relatively large effects of host resistance in reducing the severity of blast and bacterial blight; nevertheless, soil silicon added to the resistance, particularly against the more virulent strain of bacterial blight, and thereby improved seedling growth. Similar effects of silicon in reducing disease severity have been documented across a range of rice pathogens [8,15,21,22,32,[79][80][81][82]87].…”

“…Our results corroborate previous studies that showed soil silicon to reduce the severity of blast diseases and bacterial blight in rice [ 21 , 32 , 76 , 77 , 78 , 79 , 80 ]. Applications of silicon nanoparticles to foliage have also been shown to effectively reduce (by 70%) blast disease in rice [ 81 ]. In our experiments, the effect of soil silicon in reducing the severity of both diseases was weak relative to the strong effects of the corresponding resistance genes.…”

Comparison of Biogenic Amorphous Silicas Found in Common Horsetail and Oat Husk With Synthetic Amorphous Silicas

“…The grass types—among them wheat, rye, oat, rice, and others—grow smaller and are more susceptible to diseases when the accessible silica has been substantially reduced by extensive farming. BAS has been found to enhance the resistance of plants to biotic stress, e.g., diseases, such as powdery mildew and pests, such as stem boring insects ( 41 , 42 ).…”