Accumulating evidence suggests that hydrogen sulfide (H2S) is an important signaling molecule in plant environmental interactions. The consensus view amongst plant scientists is that environmental stress leads to enhanced production and accumulation of reactive oxygen species (ROS). H2S interacts with the ROS-mediated oxidative stress response network at multiple levels, including the regulation of ROS-processing systems by transcriptional or post-translational modifications. H2S–ROS crosstalk also involves other interacting factors, including nitric oxide, and can affect key cellular processes like autophagy. While H2S often functions to prevent ROS accumulation, it can also act synergistically with ROS signals in processes such as stomatal closure. In this review, we summarize the mechanisms of H2S action and the multifaceted roles of this molecule in plant stress responses. Emphasis is placed on the interactions between H2S, ROS, and the redox signaling network that is crucial for plant defense against environmental threats.

To further develop the advantages of loading artificial material units, layout rules of unit cells were investigated and presented for the first time in this study. Based on the analysis of transmission characters of metamaterial unit cells, some tapered slot antennas loaded with different unit layouts were designed. The result comparison showed that after the layout optimisation, the operation frequency band with a gain above 10 dB increased by about 13% and the gain increased by 0.4–2.6 dB in the high frequency band. In addition, the sidelobe level of H‐plane also decreased by 0.7–4 dB at different frequency points.

Photorespiratory hydrogen peroxide (H2O2) plays key roles in pathogenesis responses by triggering the salicylic acid (SA) pathway in Arabidopsis. However, factors linking intracellular H2O2 to activation of the SA pathway remain elusive. In this work, the catalase‐deficient Arabidopsis mutant, cat2, was exploited to elucidate the impact of S‐nitrosoglutathione reductase 1 (GSNOR1) on H2O2‐dependent signalling pathways. Introducing the gsnor1‐3 mutation into the cat2 background increased S‐nitrosothiol levels and abolished cat2‐triggered cell death, SA accumulation, and associated gene expression but had little additional effect on the major components of the ascorbate‐glutathione system or glycolate oxidase activities. Differential transcriptome profiles between gsnor1‐3 and cat2 gsnor1‐3 together with damped ROS‐triggered gene expression in cat2 gsnor1‐3 further indicated that GSNOR1 acts to mediate the SA pathway downstream of H2O2. Up‐regulation of GSNOR activity was compromised in cat2 cad2 and cat2 pad2 mutants in which glutathione accumulation was genetically prevented. Experiments with purified recombinant GSNOR revealed that the enzyme is posttranslationally regulated by direct denitrosation in a glutathione‐dependent manner. Together, our findings identify GSNOR1‐controlled nitrosation as a key factor in activation of the SA pathway by H2O2 and reveal that glutathione is required to maintain this biological function.

The spacing of lateral roots (LRs) along the main root in plants is driven by an oscillatory signal, often referred to as the ''root clock'' that represents a pre-patterning mechanism that can be influenced by environmental signals. Light is an important environmental factor that has been previously reported to be capable of modulating the root clock, although the effect of light signaling on the LR pre-patterning has not yet been fully investigated. In this study, we reveal that light can activate the transcription of a photomorphogenic gene HY1 to maintain high frequency and amplitude of the oscillation signal, leading to the repetitive formation of pre-branch sites. By grafting and tissue-specific complementation experiments, we demonstrated that HY1 generated in the shoot or locally in xylem pole pericycle cells was sufficient to regulate LR branching. We further found that HY1 can induce the expression of HY5 and its homolog HYH, and act as a signalosome to modulate the intracellular localization and expression of auxin transporters, in turn promoting auxin accumulation in the oscillation zone to stimulate LR branching. These fundamental mechanistic insights improve our understanding of the molecular basis of light-controlled LR formation and provide a genetic interconnection between shoot-and root-derived signals in regulating periodic LR branching.Please cite this article in press as: Duan et al., Periodic root branching is influenced by light through an HY1-HY5-auxin pathway, Current Biology (2021),

This article reports the development of an underwater imaging system and its trial on a moored surface buoy for in situ plankton monitoring of coastal waters. The imager features shadowless white light illumination by an orthogonal lamellar lighting design, resulting in high-quality underwater darkfield color imaging of planktonic particles in the size range of ∼200 µm to 40 mm and effective reduction of zooplankton phototaxis. Through raft and buoy trials, 46 804 plankton and suspending particle images have been annotated through a human-machine mutually assisted effort into a data set with 90 categories. In the meanwhile, a deep learning model based on a triclassification VGGNet-11 and multiclassification ResNet-18 convolutional neuron networks in a two-staged hierarchy has also been trained and developed. The model has been applied with human supervision to semiautomatically analyze a total of 1 545 187 images obtained from a buoy trial for six months from late spring to early winter of 2020. The high temporal resolution results well documented the variation of the mesoplankton community structure in two time series of 38 days in summer and 54 days in autumn of the target sea region. In addition, the dominant species in the trial period and a zooplankton outbreak that had threatened the safety of the nearby nuclear power plants were quantitatively Manuscript