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Most of the currently available disease resistance (R) genes have NBS (nucleotide-binding site) and LRR (leucine-rich-repeat) domain which belongs to the NBS-LRR gene family. The whole genome sequencing of Broussonetia papyrifera provides an important bioinformatics database for the study of the NBS-LRR gene family. In this study, 328 NBS-LRR family genes were identified and classified in B. papyrifera according to different classification schemes, where there are 92 N types, 47 CN type, 54 CNL type, 29 NL types, 55 TN type, and 51 TNL type. Subsequently, we conducted bioinformatics analysis of the NBS-LRR gene family. Classification, motif analysis of protein sequences, and phylogenetic tree studies of the NBS-LRR genes in B. papyrifera provide important basis for the functional study of NBS-LRR family genes. Additionally, we performed structural analysis of the chromosomal location, physicochemical properties, and sequences identified by genetic characterization. In addition, through the analysis of GO enrichment, it was found that NBS-LRR genes were involved in defense responses and were significantly enriched in biological stimulation, immune response, and abiotic stress. In addition, we found that Bp06g0955 was the most sensitive to low temperature and encoded the RPM1 protein by analyzing the low temperature transcriptome data of B. papyrifera. Quantitative results of gene expression after 48 h of Fusarium infection showed that Bp01g3293 increased 14 times after infection, which encodes RPM1 protein. The potential of NBS-LRR gene responsive to biotic and abiotic stresses can be exploited to improve the resistance of B. papyrifera. [ABSTRACT FROM AUTHOR]

Objectives: To study the possible roles of type-2C protein phosphatases (PP2Cs) which have been confirmed to play roles in the response to diverse abiotic stresses in paper mulberry, we launched a series of genomic and functional studies of BpPP2Cs. Results: Sixty-three PP2C proteins in paper mulberry (Broussonetia papyrifera) were classified into 13 clades. Four BpPP2Cs with kinase domains were verified to be highly conserved in organisms ranging from algae to dicots. Seven pairs of BpPP2C genes were found to be expanding, and 18 BpPP2C genes had orthologues in Arabidopsis. BpPP2Cs showed broad expression in different tissues; the expression levels of 18 BpPP2Cs were changed and the phosphorylation levels of seven BpPP2C proteins increased at low temperature. Cold-response elements were found in the promoter region of 31 BpPP2Cs. Finally, Bp01g0320 was found to act as a hub protein and Bp01g0512 and Bp09g1278 played key roles in the ABA-signaling pathway and MAPK cascades, respectively. Conclusion: These results suggest that the PP2C gene family of paper mulberry is evolutionarily conserved and participates the regulation of the response to cold stress, which will play a vital role in further research on phosphatases in paper mulberry. [ABSTRACT FROM AUTHOR]

There is increasing evidence for considerable interlinking between the responses to heat stress and oxidative stress, and recent researches suggest heat shock transcription factors (Hsfs) play an important role in linking heat shock with oxidative stress signals. In this paper, we present evidence that AtHsfA2 modulated expression of stress responsive genes and enhanced tolerance to heat and oxidative stress in Arabidopsis. Using Northern blot and quantitative RT-PCR analysis, we demonstrated that the expression of AtHsfA2 was induced by not only HS but also oxidative stress. By functional analysis of AtHsfA2 knockout mutants and AtHsfA2 overexpressing transgenic plants, we also demonstrated that the mutants displayed reduced the basal and acquired thermotolerance as well as oxidative stress tolerance but the overexpression lines displayed increased tolerance to these stress. The phenotypes correlated with the expression of some Hsps and APX1, ion leakage, H2O2 level and degree of oxidative injuries. These results showed that, by modulated expression of stress responsive genes, AtHsfA2 enhanced tolerance to heat and oxidative stress in Arabidopsis. So we suggest that AtHsfA2 plays an important role in linking heat shock with oxidative stress signals. [ABSTRACT FROM AUTHOR]