Bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv oryzae (Xoo) is considered as the most destructive disease of rice. The use of bactericides is among the most widely used traditional methods to control this destructive disease. The excessive and repeated use of the same bactericides is also becoming the reason behind the development of bactericide resistance. The widely used method for finding the new antimicrobial agents often involves the bacterial virulence factors as a target without affecting bacterial growth. Type III secretion system (T3SS) is a protein appendage and is considered as having essential virulence factors in most Gram-negative bacteria. Due to the conserved construct, T3SS has been regarded as an important mark for the blooming of novel antimicrobial drugs. Toward the search of new T3SS inhibitors, an alternative series of 1,3-thiazole derivatives were designed and synthesized. Their structures were characterized and confirmed by 1 H NMR, 13 C NMR, MS, and elemental analysis. All the title compounds inhibited the promoter activity of hpa1 gene significantly. Eight of them showed better inhibition than our previous T3SS inhibitor TS006 (o-coumaric acid, OCA). The treatment of Xoo with eight compounds significantly attenuated HR without affecting bacterial growth. The mRNA levels of some representative genes (hrp/hrc genes) were reduced up to different extents. In vivo bioassay results showed that eight T3SS inhibitors could reduce bacterial leaf blight and bacterial leaf streak symptoms on rice, significantly.

Gray mold, caused by Botrytis cinerea, is one of the most destructive diseases of strawberry in China. For resistance monitoring, 198 B. cinerea isolates were collected from strawberry greenhouses at 10 locations in Hubei Province. The isolates were screened for resistance to fungicides procymidone and zoxamide. In mycelium growth assays for procymidone, the mean values of effective concentration at which mycelium growth is inhibited by 50% (EC 50) for sensitive (Pro S) and resistant (Pro R) isolates were 0.25 μg/mL and 2.21 μg/mL, respectively. The frequency of Pro R isolates was 14%, and the highest frequency (48%) was observed in Yichang. Positive cross-resistance was detected for Pro R isolates to other dicarboximide fungicides, but not to phenylpyrroles. Comparative analysis of fitness parameters revealed increased osmotic sensitivity of Pro R isolates compared to Pro S ones. Sequence analysis of the dicarboximide target gene BcOs1 revealed that Pro R isolates carried either a single point mutation at codon 365 (I365S) or a pair of point mutations (Q369P and N373S). The mean EC 50 values for zoxamide sensitive (Zox S) and resistant (Zox R) isolates were 0.31 μg/mL and 7.76 μg/mL, respectively. Only six (3%) isolates from three locations were found to be resistant to zoxamide. All Zox R isolates were found resistant to carbendazim. Fitness parameters did not show significant difference between Zox R and Zox S isolates. Sequence analysis of the beta-tubulin gene in resistant isolates revealed four previously reported point mutations (E198A, E198K, F200Y and T351I). The mutation T351I was detected only in the isolates possessing E198K point mutation. Mutation F200Y was detected in a highly resistant isolate. Results of this study will be helpful for the management of fungicide resistance in B. cinerea.

Precise nucleic acid editing technologies have facilitated the research of cellular function and the development of novel therapeutics, especially the current programmable nucleases-based editing tools, such as the prokaryotic clustered regularly interspaced short palindromic repeats (CRISPR)-associated nucleases (Cas). As CRISPR-based therapies are advancing toward human clinical trials, it is important to understand how natural genetic variation in the human population may affect the results of these trials and even patient safety. The development of "base-editing" technique allows the direct, stable transformation of target DNA base into an alternative in a programmable way, without DNA double strand cleavage or a donor template. Genome-editing techniques hold promises for the treatment of genetic disease at the DNA level by blocking the sequences associated with disease from producing disease-causing proteins. Currently, scientists can select the gene they want to modify, use the Cas9 as a "molecular cutter" to cut it out, and transform it into a more desirable version. In this review, we focus on the recent advances of CRISPR/Cas system by outlining the evolutionary and biotechnological implications of current strategies for improving the specificity and accuracy of these genome-editing technologies.

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Botrytis cinerea, the causal agent of gray mold, can result in considerable preharvest and postharvest losses in many economically valuable plant species. Fungicides were widely used to minimize such losses, but fungicide resistances were detected frequently. In the present study, we collected 164 isolates from nectarine and cherry in China and tested the sensitivity to six fungicides. Among the tested isolates, 71 (43.3%) were resistant to azoxystrobin, 14 (8.5%) to cyprodinil, 7 (4.3%) to boscalid, 4 (2.4%) to carbendazim, 1 (0.6%) to iprodione, and no isolates were found to be resistant to fludioxonil. The EC50 value and resistance factor (RF) of resistant isolates were determined. Fitness analysis showed that there were no significant differences between sensitive and resistant isolates for osmotic stress and pathogenicity, while more conidia production was observed for some resistant isolates. Control efficacy of fungicides showed that the resistant isolates could not be controlled efficiently by using corresponding fungicides. The point mutation G143A was detected in the Cyt b gene of the isolates resistant to azoxystrobin, while the point mutation H272R of SdhB gene was confirmed in boscalid-resistant isolates, and mutations E198V/A of TUB2 gene and mutation I365S of BcOs1 occurred in carbendazim-resistant and iprodione-resistant isolates, respectively. These results indicate that the occurrence of fungicide resistance greatly threatens the management of gray mold on stone fruits nectarine and cherry.