Summary Quantifying the abundances of fungi is key to understanding natural variation in mycorrhizal communities in relation to plant ecophysiology and environmental heterogeneity. High‐throughput metabarcoding approaches have transformed our ability to characterize and compare complex mycorrhizal communities. However, it remains unclear how well metabarcoding read counts correlate with actual read abundances in the sample, potentially limiting their use as a proxy for species abundances. Here, we use droplet digital PCR (ddPCR) to evaluate the reliability of ITS2 metabarcoding data for quantitative assessments of mycorrhizal communities in the orchid species Neottia ovata sampled at multiple sites. We performed specific ddPCR assays for eight families of orchid mycorrhizal fungi and compared the results with read counts obtained from metabarcoding. Our results demonstrate a significant correlation between DNA copy numbers measured by ddPCR assays and metabarcoding read counts of major mycorrhizal partners of N. ovata, highlighting the usefulness of metabarcoding for quantifying the abundance of orchid mycorrhizal fungi. Yet, the levels of correlation between the two methods and the numbers of false zero values varied across fungal families, which warrants cautious evaluation of the reliability of low‐abundance families. This study underscores the potential of metabarcoding data for more quantitative analyses of mycorrhizal communities and presents practical workflows for metabarcoding and ddPCR to achieve a more comprehensive understanding of orchid mycorrhizal communities.

New PhytologistVolume 239, Issue 2 p. 445-448 Cover and Issue InformationFree Access Issue Information First published: 13 June 2023 https://doi.org/10.1111/nph.18242AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Graphical Abstract Cover Legend Anthocyanin accumulation in nutrient-stressed crops can serve as bioindicator for targeted fertilizer application. Collage of images featuring rapeseed (Brassica napus), celery (Apium graveolens) and cauliflower (Brassica oleracea var. botrytis). Image courtesy of Mareike Jezek and Christoph-Martin Geilfus (Jezek et al., pp. 494–505). Volume239, Issue2July 2023Pages 445-448 RelatedInformation

New PhytologistVolume 239, Issue 1 p. 1-4 Cover and Issue InformationFree Access Issue Information First published: 01 June 2023 https://doi.org/10.1111/nph.18241AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Graphical Abstract Cover Legend Seeing plants in a new light: novel laser imaging technology enables rapid data acquisition in full color. Image shows the woody stem of Gnetum woodsonianum created using Laser Ablation Tomography (LATscan). Image courtesy of Benjamin Hall (Cunha Neto et al., pp. 429–444). Volume239, Issue1July 2023Pages 1-4 RelatedInformation

New PhytologistVolume 238, Issue 6 p. 2255-2258 Cover and Issue InformationFree Access Issue Information First published: 17 May 2023 https://doi.org/10.1111/nph.18240AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Graphical Abstract Cover Legend Several cacti rise above the desert floor at sunset, near San Carlos, Mexico. Image courtesy of Benjamin Wong Blonder (Blonder et al., pp. 2271–2283 & 2313–2328). Volume238, Issue6June 2023Pages 2255-2258 RelatedInformation

New PhytologistVolume 238, Issue 5 p. 1745-1748 Cover and Issue InformationFree Access Issue Information First published: 26 April 2023 https://doi.org/10.1111/nph.18239AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Graphical Abstract Cover Legend Ant-inhabited Caularthron bilamellatum (Orchidaceae) growing on a branch of an Annona glabra tree in Panama. Image courtesy of Christian Gegenbauer (Gegenbauer et al., pp. 2210–2223). Volume238, Issue5June 2023Pages 1745-1748 RelatedInformation

New Phytologist 224 (2019), 875–885, doi: 10.1111/nph.15813. Since its publication, the authors of Iida et al. (2019) have highlighted an error in their article. In Fig. 5(b), the scale of values provided on the y-axis was incorrect. The corrected Fig. 5 is shown below. We apologize to our readers for this mistake. Corrected Fig. 5:

In natural long days, the florigen gene FLOWERING LOCUS T (FT) shows a bimodal expression pattern with morning and dusk peaks in Arabidopsis. This pattern differs from the one observed in the laboratory, and little is known about underlying mechanisms. A red : far-red (R : FR) ratio difference between sunlight and fluorescent light causes this FT pattern mismatch. We showed that bimodal FT expression patterns were induced in a day longer than 14 h with sunlight R : FR (= c. 1) conditions. By circadian gating experiments, we found that cumulative exposure of R : FR-adjusted light (R : FR ratio was adjusted to 1 with FR supplement) spanning from the afternoon to the next morning required full induction of FT in the morning. Conversely, only 2 h of R : FR adjustment in the late afternoon was sufficient for FT induction at dusk. We identified that phytochrome A (phyA) is required for the morning FT expression in response to the R : FR adjustment on the previous day. As a part of this mechanism, we showed that PHYTOCHROME-INTERACTING FACTOR 7 contributes to FT regulation. Our results suggest that phyA-mediated high-irradiance response and the external coincidence mechanism contribute to morning FT induction under natural long-day conditions.

Crop loss due to soil salinization is a global threat to agriculture. Nitric oxide (NO) and ethylene involve in multiple plant tolerance. However, their interaction in salt resistance remains largely elusive. We tested the mutual induction between NO and ethylene, and then identified an 1-aminocyclopropane-1-carboxylate oxidase homolog 4 (ACOh4) that influences ethylene synthesis and salt tolerance through NO-mediated S-nitrosylation. Both NO and ethylene positively responded to salt stress. Furthermore, NO participated in salt-induced ethylene production. Salt tolerance evaluation showed that function of NO was abolished by inhibiting ethylene production. Conversely, function of ethylene was little influenced by blocking NO generation. ACO was identified as the target of NO to control ethylene synthesis. In vitro and invivo results suggested that ACOh4 was S-nitrosylated at Cys172, resulting in its enzymatic activation. Moreover, ACOh4 was induced by NO through transcriptional manner. Knockdown of ACOh4 abolished NO-induced ethylene production and salt tolerance. At physiological status, ACOh4 positively regulates the Na+ and H+ efflux, and keeps K+ /Na+ homeostasis by promoting salt-resistive genes' transcripts. Our findings validate a role of NO-ethylene module in salt tolerance and uncover a novel mechanism of how NO promoting ethylene synthesis against adversity.

This article is a Commentary on Denk et al. (2023), 238: 2668–2684.

New PhytologistVolume 238, Issue 4 p. 1333-1336 Cover and Issue InformationFree Access Issue Information First published: 12 April 2023 https://doi.org/10.1111/nph.18238AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Graphical Abstract Cover Legend Scanning electron micrograph of emerging aquatic adventitious root from the stem of deepwater rice (false-coloured image). Image courtesy of Chen Lin (Lin et al., pp. 1403–1419). Volume238, Issue4May 2023Pages 1333-1336 RelatedInformation