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Anthracycline-induced liver injury (AILI) is becoming an increasingly serious and potential clinical complication and is linked to reactive oxygen species (ROS) production and subsequent inflammatory response. Herein, we demonstrated that artificial Prussian blue nanozymes (PBZs) prevented daunorubicin-induced liver injury, a prototype of AILI, by attenuating ROS production and regulating inflammation. PBZs exhibited multienzyme activity and could scavenge ROS and free radicals. At the cellular level, PBZs could effectively eliminate ROS, suppress hepatocyte apoptosis, reduce deoxyribonucleic acid damage, and decrease the levels of inflammatory cytokines and chemokines. According to the results of the in vivo study, pretreatment with PBZs also resulted in a desirable protective effect against AILI, as indicated by both a decrease in biochemical indicator levels and hepatocyte necrosis. PBZs upregulated antioxidative genes by activating the Nrf2 pathway to reduce oxidative stress. Meanwhile, PBZs counteracted the inflammatory response based on the decreased expression levels of myeloperoxidase and F4/80 in the liver. Collectively, our findings indicate that PBZ-based nanotherapy is a novel strategy for protecting against AILI.

Metal–organic frameworks (MOFs) is a class of crystalline solid materials, whose well-defined pore structure makes them good candidates for the mimicking of natural enzymes. On one hand, MOFs are suitable for enzyme immobilization due to their porosity and multiplex structures. On the other hand, transition metal nodes containing MOFs themselves can play as biomimetic catalysts. Typically, Prussian blue (PB) is meaningful and influencing for developing MOF. Not strictly, PB is the first MOF structure that has been used for electrode modification owing to their good redox activity and high electrochemical stability. These characteristics also endow PB the potential to become an “artificial enzyme”. In this chapter, the use of MOFs and Prussian blue nanoparticles (PBNPs) for mimicking natural enzymes is discussed. History, structure, and properties of MOFs and PB are elaborated. The peroxidase, catalase, superoxide dismutase, and ascorbic acid oxidase-like activities of PBNPs are summarized. The catalytic mechanisms are also discussed. Selected examples for in vitro biodetection, in vivo bioimaging, and therapeutics are covered to highlight the broad applications of MOFs and PBNPs based on their multienzyme-like activities.

As a major component of ideal plant architecture, leaf angle especially flag leaf angle (FLA) makes a large contribution to grain yield in rice. We utilized a worldwide germplasm collection to elucidate the genetic basis of FLA that would be helpful for molecular design breeding in rice. Genome-wide association studies (GWAS) identified a total of 40 and 32 QTLs for FLA in Wuhan and Hainan, respectively. Eight QTLs were commonly detected in both conditions. Of these, 2 and 3 QTLs were identified in the indica and japonica subpopulations, respectively. In addition, the candidates of 5 FLA QTLs were verified by haplotype-level association analysis. These results indicate diverse genetic bases for FLA between the indica and japonica subpopulations. Three candidates, OsbHLH153, OsbHLH173 and OsbHLH174, quickly responded to BR and IAA involved in plant architecture except for OsbHLH173, whose expression level was too low to be detected; their overexpression in plants increased rice leaf angle. Together with previous studies, it was concluded that all 6 members in bHLH subfamily 16 had the conserved function in regulating FLA in rice. A comparison with our previous GWAS for tiller angle (TA) showed only one QTL had pleiotropic effects on FLA and TA, which explained low similarity of the genetic basis between FLA and TA. An ideal plant architecture is expected to be efficiently developed by combining favorable alleles for FLA from indica with favorable alleles for TA from japonica by inter-subspecies hybridization., Author summary Rice leaf angle is a major component of ideal plant architecture that determines plant density. Many leaf angle-related genes have been characterized based on mutants, but natural variations of these genes and potential values in genetic improvement have not been evaluated. Here we explore the genetic basis of rice FLA in rice by GWAS. Dozens of quantitative trait loci (QTLs) have been identified, but few FLA QTLs have been commonly detected between indica and japonica subpopulations. Alleles for small leaf angle mostly come from indica rice. Three novel OsbHLH genes have been confirmed to regulate leaf angle by overexpression. Together with previous studies, all 6 members of bHLH subfamily 16 have a conserved function in regulating leaf angle. Only one QTL has been identified with pleiotropic effects on FLA and TA in the same collection, indicated the diverse genetic basis between FLA and TA. Alleles for small TA mostly come from japonica rice. We suggest to breed compact plant type cultivars by simultaneously utilizing favorable alleles for FLA and TA via inter-subspecies hybridization.

Herein we reported Prussian blue nanoparticles (PBNPs) possess ascorbic acid oxidase (AAO)- and ascorbic acid peroxidase (APOD)-like activities, which suppressed the formation of harmful H2O2 and finally inhibited the anti-cancer efficiency of ascorbic acid (AA). This newly revealed correlation between iron and AA could provide new insight for the studies of nanozymes and free radical biology.

Tiller angle is one of the most important components of the ideal plant architecture that can greatly enhance rice grain yield. Understanding the genetic basis of tiller angle and mining favorable alleles will be helpful for breeding new plant-type varieties. Here, we performed genome-wide association studies (GWAS) to identify genes controlling tiller angle using 529 diverse accessions of Oryza sativa including 295 indica and 156 japonica accessions in two environments. We identified 7 common quantitative trait loci (QTLs), including the previously reported major gene Tiller Angle Control 1 (TAC1), in the two environments, 10 and 13 unique QTLs in Hainan and Wuhan, respectively. More QTLs were identified in indica than in japonica, and three major QTLs (qTA3, qTA1b/DWARF2 (D2) and qTA9c/TAC1) were fixed in japonica but segregating in indica, which explained the wider variation observed in indica compared with that in japonica. No common QTLs were identified between the indica and japonica subpopulations. Mutant analysis for the candidate gene of qTA3 on chromosome 3 indicated a novel gene, Tiller Angle Control 3 (TAC3), encoding a conserved hypothetical protein controlling tiller angle. TAC3 is preferentially expressed in the tiller base. The ebisu dwarf (d2) mutant exhibited a decreased tiller angle, in addition to its previously described abnormal phenotype. A nucleotide diversity analysis revealed that TAC3, D2 and TAC1 have been subjected to selection during japonica domestication. A haplotype analysis identified favorable alleles of TAC3, D2 and TAC1, which may be used for breeding plants with an ideal architecture. In conclusion, there is a diverse genetic basis for tiller angle between the two subpopulations, and it is the novel gene TAC3 together with TAC1, D2, and other newly identified genes in this study that controls tiller angle in rice cultivars., Author Summary Tiller angle is the key component of plant architecture that greatly affect grain yield. However, few tiller angle-related genes that can be used for improving rice plant architecture have been isolated based on natural variation. Here, we identified 7 common tiller angle-related QTLs by a genome-wide association study, including the previously reported major gene TAC1, in two environments in the 529 diverse rice accessions and dozens of QTLs specially identified in one environment. Two QTLs were validated by mutant analysis: A novel gene TAC3, encoding a conserved hypothetical protein and preferentially expressing in the tiller base, was the candidate gene of qTA3; d2 mutant exhibited a decreased tiller angle, in addition to its previously described abnormal phenotype. A haplotype analysis identified favorable alleles of TAC3, D2 and TAC1 in indica, which may be used for breeding plants with an ideal architecture, while they were all subjected to selection and fixed in japonica. In conclusion, there is a diverse genetic basis for tiller angle between the two subpopulations, and it is the novel gene TAC3, together with TAC1 and D2 that greatly controls tiller angle in rice cultivars.

Panicle architecture determines the number of spikelets per panicle (SPP) and is highly associated with grain yield in rice ( L.). Understanding the genetic basis of panicle architecture is important for improving the yield of rice grain. In this study, we dissected panicle architecture traits into eight components, which were phenotyped from a germplasm collection of 529 cultivars. Multiple regression analysis revealed that the number of secondary branch (NSB) was the major factor that contributed to SPP. Genome-wide association analysis was performed independently for the eight particle architecture traits observed in the and rice subpopulations compared with the whole rice population. In total, 30 loci were associated with these traits. Of these, 13 loci were closely linked to known panicle architecture genes, and 17 novel loci were repeatedly identified in different environments. An association signal cluster was identified for NSB and number of spikelets per secondary branch (NSSB) in the region of 31.6 to 31.7 Mb on chromosome 4. In addition to the common associations detected in both and subpopulations, many associated loci were unique to one subpopulation. For example, and were specifically associated with panicle length (PL) in and rice, respectively. Moreover, the -mediated flowering genes and were associated with the formation of panicle architecture in rice. These results suggest that different gene networks regulate panicle architecture in and rice.

CCT domain-containing genes generally control flowering in plants. Currently, only six of the 41 CCT family genes have been confirmed to control flowering in rice. To efficiently identify more heading date-related genes from the CCT family, we compared the positions of heading date QTLs and CCT genes and found that 25 CCT family genes were located in the QTL regions. Association mapping showed that a total of 19 CCT family genes were associated with the heading date. Five of the seven associated genes within QTL regions and two of four associated genes outside of the QTL regions were confirmed to regulate heading date by transformation. None of the seven non-associated genes outside of the QTL regions regulates heading date. Obviously, combination of candidate gene-based association mapping with linkage analysis could improve the identification of functional genes. Three novel CCT family genes, including one non-associated (OsCCT01) and two associated genes (OsCCT11 and OsCCT19) regulated the heading date. The overexpression of OsCCT01 delayed flowering through suppressing the expression of Ehd1, Hd3a and RFT1 under both long day and short day conditions. Potential functions in regulating heading date of some untested CCT family genes were discussed.