Identification and characterization of tomato gibberellin 2-oxidases (GA2oxs) and effects of fruit-specific SlGA2ox1 overexpression on fruit and seed growth and development

Gibberellins(GAs)play a crucial role in growth and development of the tomato fruit.Previously published studies focusing on the effect of GAs on tomato fruits used chemical treatments,constitutive overexpression or silencing of GA biosynthetic and catabolic genes globally throughout the plant.Fruit-specific overexpression of GA catabolic enzyme genes GA2-oxidases(GA2oxs),however,may provide an alternative method to study the role of endogenous GAs on the fruit development.In this study,we have identified 11 SlGA2ox proteins in tomato that are classified into three subgroups.Motif analysis and multiple sequence alignments have demonstrated that all SlGA2oxs,except SlGA2ox10,have similar motif compositions and high-sequence conservation.Quantitative reverse transcription-PCR analysis has showed that SlGA2oxs exhibit differential expression patterns in tomato fruits at different developmental stages.When the fruit-specific promoter TFM7 was used to control the expression of SlGA2ox1,we observed no changes in growth and development of vegetative organs.However,fruit weight,seed number and germination rate were significantly affected.We also treated tomato fruits with GA biosynthesis inhibitor and observed phenotypes similar to those of the transgenic fruits.Furthermore,we have demonstrated that expression of cell expansion and GA responsive genes were downregulated in transgenic tomato fruits,supporting that overexpression of the SlGA2ox1 leads to reduction in endogenous GAs.This study provides additional evidence that endogenous GAs and the SlGA2ox1 gene play an important role in controlling on fruit weight,seed development and germination in tomato plant.

Effectiveness and feasibility of transradial approaches for primary percutaneous coronary intervention in patients with acute myocardial infarction

Objective： To evaluate the efficacy and feasibility of the transradial approach for primary percutaneous coronary intervention （PCI） in patients with acute myocardial infarction（AMI）. Methods： 195 patients with acute myocardial infarction were randomly divided into two groups according to the different PCI operation pathways. 105 cases were assigned to the transfemoral artery group and 90 cases to the transradial artery group. We analyzed the data from the two groups, including the achievement ratio of paracentesis, cannulation time, the time from local anesthesia to the first time balloon inflation, the time of the total procedure, achievement ratio of PCI, incidence rate of vascular complications, total duration of hospitalization, and the six-month follow-up results in both groups. Results： Our results showed that the achier ement ratio of arteriopuncture, cannulafion time and the time from local anesthesia to the first time balloon inflation in the transradial and transfemoral groups were 98.9% vs. 100%, 3.15 ± 1.56min vs. 2.86 ± 0.97 min, and 18.56 ± 4.37 min vs. 17.75 ± 3.21 min, respectively. These differences between the two groups were not statistically significant. The total operating time was 29.75 ± 4.38 rain for the transradial group and 27.89 ± 3.95 min（P 〈 0.05） for the transfemoral group. The operation achievement ratio in the transradial group was 96.7%, and 96.2% in the transfemoral group. The incidence of puncture point complications was 2.2% in the transradial group and 11.4% in the transfemoral group, and this difference was significant. The duration of hospitalization was 10.56 ± 2.85 days for the transradial group and 13.78 ± 3.15 days（P 〈 0.05） for the transfemoral group. At the six-month follow-up, the rate of survival without cardiac event was 86.1% vs. 86.4% respectively in the transradial and transfemoral groups（P 〉 0.05）. Conclusion： The transradial approach was as effective as the transfemoral approach, and there were fewer puncture point complications as well as a shorter span of hospitalization in the transradial group. PCI via the transradial approach is safe, effective and feasible in patients with AMI.

Evolution and roles of cytokinin genes in angiosperms 1:Do ancient IPTs play housekeeping while non-ancient IPTs play regulatory roles?

Isopentenyltransferase(IPT)genes,including those encoding ATP/ADP-IPTs and tRNA-IPTs,control the rate-limiting steps of the biosynthesis of N6-(Δ2-isopentenyl)adenine(iP)-type and trans-zeatin(tZ)-type cytokinins and cis-zeatin(cZ)-type cytokinins,respectively.However,the evolution and roles of these IPTs in angiosperms are not well understood.Here,we report comprehensive analyses of the origins,evolution,expression patterns,and possible roles of ATP/ADP-IPTs and tRNA-IPTs in angiosperms.We found that Class I and II tRNA-IPTs likely coexisted in the last common ancestor of eukaryotes,while ATP/ADP-IPTs likely originated from a Class II tRNA-IPT before the divergence of angiosperms.tRNA-IPTs are conservatively retained as 2–3 copies,but ATP/ADP-IPTs exhibit considerable expansion and diversification.Additionally,tRNA-IPTs are constitutively expressed throughout the plant,whereas the expression of ATP/ADP-IPTs is tissue-specific and rapidly downregulated by abiotic stresses.Furthermore,previous studies and our present study indicate that ATP/ADP-IPTs and their products,iPs/tZs,may regulate responses to environmental stresses and organ development in angiosperms.We therefore hypothesize that tRNA-IPTs and the associated cZs play a housekeeping role,whereas ATP/ADP-IPTs and the associated iP/tZ-type cytokinins play regulatory roles in organ development and stress responses in angiosperms,which echoes the conclusions and hypothesis presented in the accompanying study by Wang,X.et al Evolution and roles of cytokinin genes in angiosperms 2:Do ancient CKXs play housekeeping roles while non-ancient CKXs play regulatory roles?Hortic Res https://doi.org/10.1038/s41438-020-0246-z.