Combined Transcriptome and Metabolome Analysis of Alfalfa Response to Thrips Infection

Thrips (Thysanoptera: Thripidae) is a major insect pest for alfalfa which can result in decreased plant nutrients, low yields, and even plant death. To identify the differentially expressed genes and metabolites in response to thrips in alfalfa, a combination of metabolomics and transcriptomics was employed using alfalfa (Caoyuan No. 2) with and without thrips infestation. The results showed that the flavonoid biosynthesis and isoflavonoid biosynthesis pathways were the most significantly enriched pathways in response to thrips infection, as shown by the combined transcriptome and metabolome analysis. The transcriptome results showed that SA and JA signal transduction and PAPM-triggered immunity and the MAPK signaling pathway–plant pathways played a crucial role in thrips-induced plant resistance in alfalfa. In addition, we found that thrips infestation could also induce numerous changes in plant primary metabolism, such as carbohydrate and amino acid metabolism as compared to the control. Overall, our results described here should improve fundamental knowledge of molecular responses to herbivore-inducible plant defenses and contribute to the design of strategies against thrips in alfalfa.

Nano Silica application for inducing rice resistance and the possibility for Ytterbium Rare Earth Elements green mining

There is a growing interest and recognition of Silicon (Si) in plants to increase growth, productivity, and plant resistance. This research examines the role of Nano Silica to increase yield and resistance. This study set out to assess the effect of hydrophilic fumed Nano Silica application with the frequency of 1×, 2×, 3×, and 4× applications respectively with three replications using RCBD as well as SEM-EDX and XRF analysis. Nano Silica frequencies showed a distinctive decrease of damage intensity at the 3× and 4× applications. The rice husk increases of metal-like surface appearance as more Nano Silica frequency was applied. It is proposed that Nano Si induced plant resistance through the modification of surface layer and stronger plant tolerance against environmental stress. The most unexpected observation to emerge was the Ytterbium (Yb) concentration known as a Rare Earth Elements at the 3× and 4× Nano Si applications. This indicates that Nano Silica application provides insights and opportunities to Nano Si application on Rice for the purpose of acquiring Ytterbium from farmland. Nano Silica can play an important role as a new method in addressing the Ytterbium green mining.

Salicylic acid and its role in induced plant resistance to biotic stress

Salicylic acid is a natural signaling molecule that plays a key role in establishing and transmitting plant protection signals from phytopathogens. Salicylic acid, by modulating the expression of protective genes and changing the activity of antioxidant enzymes, can regulate oxidative processes associated with plant protective reactions. This review article reviews studies that provide insight into the functioning of salicylic acid in plant immunity

Exploring Elicitors of the Beneficial Rhizobacterium Bacillus amyloliquefaciens SQR9 to Induce Plant Systemic Resistance and Their Interactions With Plant Signaling Pathways

Beneficial rhizobacteria have been reported to produce various elicitors that induce plant systemic resistance, but there is little knowledge concerning the relative contribution of multiple elicitors from a single beneficial rhizobacterium on the induced systemic resistance in plants and the interactions of these elicitors with plant signaling pathways. In this study, nine mutants of the plant growth–promoting rhizobacterium Bacillus amyloliquefaciens SQR9 deficient in producing the extracellular compounds, including fengycin, bacillomycin D, surfactin, bacillaene, macrolactin, difficidin, bacilysin, 2,3-butandiol, and exopolysaccharides, were tested for the induction of systemic resistance against Pseudomonas syringae pv. tomato DC3000 and Botrytis cinerea and the transcription of the salicylic acid, jasmonic acid, and ethylene signaling pathways in Arabidopsis. Deficiency in producing any of these compounds in SQR9 significantly weakened the induced plant resistance against these phytopathogens. These SQR9-produced elicitors induced different plant defense genes. For instance, the enhancement of 1,3-glucanase (PR2) by SQR9 was impaired by a deficiency of macrolactin but not surfactin. SQR9 mutants deficient in the lipopeptide and polyketide antibiotics remained only 20% functional for the induction of resistance-related gene transcription. Overall, these elicitors of SQR9 could act synergistically to induce plant systemic resistance against different phytopathogens through different signaling pathway genes, and the bacterial antibiotics are major contributors to the induction.