TLC (TRAM/LAG/CRN8) proteins play important roles in ceramide metabolism and mycotoxin resistance. Herein a comparative genomics analysis of TLCs was performed in 31 plant and 3 species from other kingdoms, with an emphasis mainly on maize. TLCs were conserved across kingdoms and expanded in angiosperms, largely due to whole-genome/segmental duplication (WGD/SD) under purifying selection. Phylogeny reconstruction by maximum-likelihood method uncovered five TLC clades, subsequently named as TRAM/LAG, CLN8, PS-TLC, TM136 and TLCD clades. Each clade of TLCs shared specific transmembrane regions and motif composition. Divisions of conserved motifs to subunits may have occurred in TM136-type TLCs. Focusing on maize, five WGD and two DNA-mediated transposed duplication (TD) pairs were discovered, accounting for 61.11% ZmTLCs. Combined with further expression analysis, significant divergence was found in expression patterns between most maize WGD pairs, indicating subfunctionalization or/and neofunctionalization. Moreover, ZmTLC5, a deduced parental copy in a TD pair, was highly induced under FB1 and fungus pathogen injection and exhibited potential capacity to respond to environmental stimuli. Additionally, population genetics analysis showed that ZmTLC10 in the CLN8-clade may have experienced significant positive selection and differentiated between wild and inbred maize populations. Overall, our results help to decipher the evolutionary history of TLCs in maize and plants, facilitating further functional analysis of them.

To improve long-term graft patient outcomes and develop more effective antirejection therapies, noninvasive monitoring of acute cellular rejection (ACR) after organ transplantation is urgently needed. As a biomarker of ACR, Granzyme B (GrB) is expected to be applied in the noninvasive monitoring of ACR. Herein, we have developed a method for detecting the GrB activity based on the target-initiated great change in electrochemical steric hindrance by designing a nanoprobe. The nanoprobe is prepared by conjugating a specific peptide, which is responsive to GrB cleavage activity, to gold nanoparticles (AuNPs). Meanwhile, a piece of DNA sequence with G-quadruplex (G4) is attached at the distal end of the peptide. Upon exposure to GrB, the peptide substrate is cleaved to eliminate the steric hindrance between inter-nanoprobes as well as nanoprobe and DNA tetrahedron (TDN), allowing the released DNA strand to hybridize with TDN, giving sensitive signal output. The method can also be used to detect GrB activity in complex biological settings, so it has a great potential for monitoring GrB activity in the blood or urine of graft patients.

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Drought is a key factor affecting plant growth and development. Heat shock transcription factors (Hsfs) have been reported to respond to diverse abiotic stresses, including drought stress. In the present study, functional characterization of maize heat shock transcription factor 05 (ZmHsf05) gene was conducted. Homologous analysis showed that ZmHsf05 belongs to Class A2 Hsfs. The mRNA expression level of ZmHsf05 can be affected by drought, high temperature, salt, and abscisic acid (ABA) treatment. Ectopic overexpression of ZmHsf05 in rice (Oryza sativa) could significantly enhance the drought tolerance. Faced with drought stress, transgenic rice exhibited better phenotypic performance, higher survival rate, higher proline content, and lower leaf water loss rate, compared with wild-type plant Zhonghua11. Additionally, we assessed the agronomic traits of seven transgenic rice lines overexpressing ZmHsf05 and found that ZmHsf05 altered agronomical traits in the field trials. Moreover, rice overexpressing ZmHsf05 was more sensitive to ABA and had either a lower germination rate or shorter shoot length under ABA treatment. The transcription level of key genes in the ABA synthesis and drought-related pathway were significantly improved in transgenic rice after drought stress. Collectively, our results showed that ZmHsf05 could improve drought tolerance in rice, likely in an ABA-dependent manner.