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Abstract Lignin is main composition of agricultural biomass which can be decomposed through enzymatic hydrolysis by fungi. However, there are still needs to identify more efficient and effective fungal stain for biomass valorization. In this study, lignin degrading fungi from birch forest were screened for sustainable degradation of waste agricultural straws. The most effective strain was identified as Cerrena unicolor GC.u01 using 18 S rDNA gene-sequencing technology. Three different crop straws (corn stalk, rice and wheat straws) were used for the biotreatment studies. The activities of lignin degrading enzymes, laccase (Lac), cellulase and xylanase, secreted by C. unicolor were also determined. Scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR) and thermal gravimetric analyzer (TGA) were further used to monitor the effects of the biotreatment process. The results showed that C. unicolor degraded 34.3% rice straw lignin, a percentage which was higher than other isolated strains after 15 d straw liquid fermentation. The highest Lac activity (8.396 U•mL− 1) was observed with corn stalk on the 7 d. Cellulase and xylanase activities, in the same biomass, were higher than those of wheat and rice straws after 15 d. Furthermore, SEM, FTIR and TGA analyses showed that C. unicolor pretreatment process had significant effects on corn stalk, rice and wheat straws’ structures. The newly isolated stain of C. unicolor demonstrated high lignin degradation potential that can provide effective, ecofriendly means of valorizing biomass to industrial useable raw-material.

Osa-miR439 is a rice-specific microRNA family. Here we showed that Osa-miR439 acted as a negative regulator in rice immunity against blast fungus Magnaporthe oryzae. Osa-miR439 differentially responded to M. oryzae between susceptible and resistant rice accessions. The accumulation of Osa-miR439 was constitutively more in the susceptible accession than in the resistant one. Transgenic lines overexpressing Osa-miR439a (OX439a) showed higher susceptibility associating with lower induction of defense-related genes and less hydrogen peroxide (H2O2) accumulation at the infection sites than the control plants. In contrast, transgenic lines expressing a target mimic of Osa-miR439 (MIM439) displayed compromised susceptibility associating with increased H2O2 accumulation. Furthermore, we found that the expression of three predicted target genes was decreased in OX439a but increased in MIM439 in comparison to control plants, and this expression was differential in susceptible and resistant accessions upon M. oryzae infection, indicating that Osa-miR439a may regulate rice blast resistance via these genes. Our results unveiled the role of Osa-miR439a in rice blast resistance and provided the potentiality to improve the blast resistance via miRNA.

Diaphorina citri Kuwayama is a serious insect pest of citrus worldwide due to the capacity to transmit causal agent of the huanglongbing. Mineral oils are recommended in the integrated pest management programs to prevent resistance development. The primary objective of this study was to determine emergence inhibition and antifeedant effect of three mineral oils with similar n-paraffin carbon number against D. citri. The results of topical contact toxicity showed that Antong was the most toxic with 50% lethal concentration value of 189 ng/insect. Each mineral oil at the concentrations of 0.1, 0.2 and 0.5% (v/v) significantly inhibited the emergence of adults from treated fifth-instar nymphs, and 0.5% (v/v) of the oils had a long residue activity that they inhibited over 56% adult emergence up to 10 days. We found significant repellency of D. citri from citrus tree resets that were treated with mineral oils compared with control. 0.5% (v/v) of the mineral oils significantly inhibited feeding of D. citri adults with reduction of 39–68% honeydew, and the nymphs that fed on citrus leaves treated with different concentrations raised heads and upper abdomens to form a half-erect posture. Our studies indicated that mineral oils could effectively reduce or suppress the spread of HLB by repellency and less feeding, as well as emergence inhibition to reduce D. citri populations. [ABSTRACT FROM AUTHOR]