After germination, plants enter juvenile vegetative phase and then transition to an adult vegetative phase before producing reproductive structures. The character and timing of the juvenile-to-adult transition vary widely between species. In annual plants, this transition occurs soon after germination and usually involves relatively minor morphological changes, whereas in trees and other perennial woody plants it occurs after months or years and can involve major changes in shoot architecture. Whether this transition is controlled by the same mechanism in annual and perennial plants is unknown. In the annual forb Arabidopsis thaliana and in maize (Zea mays), vegetative phase change is controlled by the sequential activity of microRNAs miR156 and miR172. miR156 is highly abundant in seedlings and decreases during the juvenile-to-adult transition, while miR172 has an opposite expression pattern. We observed similar changes in the expression of these genes in woody species with highly differentiated, well-characterized juvenile and adult phases (Acacia confusa, Acacia colei, Eucalyptus globulus, Hedera helix, Quercus acutissima), as well as in the tree Populus x canadensis, where vegetative phase change is marked by relatively minor changes in leaf morphology and internode length. Overexpression of miR156 in transgenic P. x canadensis reduced the expression of miR156-targeted SPL genes and miR172, and it drastically prolonged the juvenile phase. Our results indicate that miR156 is an evolutionarily conserved regulator of vegetative phase change in both annual herbaceous plants and perennial trees.

Porous CoFe O /C NRAs supported on nickel foam@NC (denoted as NF@NC-CoFe O /C NRAs) are directly fabricated by the carbonization of bimetal-organic framework NRAs grown on NF@poly-aniline(PANI), and they exhibit high electrocatalytic activity, low overpotential, and high stability for the oxygen evolution reaction in alkaline media.

Postsynthetic ion exchange of [Co2(μ-Cl)2(btta)] (MAF-X27-Cl, H2bbta =1H,5H-benzo(1,2-d:4,5-d')bistriazole) possessing open metal sites on its pore surface yields a material [Co2(μ-OH)2(bbta)] (MAF-X27-OH) functionalized by both open metal sites and hydroxide ligands, giving drastically improved electrocatalytic activities for the oxygen evolution reaction (an overpotential of 292 mV at 10.0 mA cm(-2) in 1.0 M KOH solution). Isotope tracing experiments further confirm that the hydroxide ligands are involved in the OER process to provide a low-energy intraframework coupling pathway.

A dinuclear cobalt complex [Co (OH)L ](ClO ) (1, L =N[(CH ) NHCH (m-C H )CH NH(CH ) ] N) displays high selectivity and efficiency for the photocatalytic reduction of CO to CO in CH CN/H O (v/v=4:1) under a 450 nm LED light irradiation, with a light intensity of 100 mW cm . The selectivity reaches as high as 98 %, and the turnover numbers (TON) and turnover frequencies (TOF) reach as high as 16896 and 0.47 s , respectively, with the calculated quantum yield of 0.04 %. Such high activity can be attributed to the synergistic catalysis effect between two Co ions within 1, which is strongly supported by the results of control experiments and DFT calculations.

This paper highlights the current key progress on HOF-based materials, including their design, structural characteristics, and applications.