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PubMed2026

The transcription factors GmBBX17 and GmSTFs antagonistically regulate shade avoidance in soybean by oppositely modulating GmSRG1 transcription.

High-density planting represents a promising strategy to enhance crop productivity. However, this agronomic practice inevitably triggers shade avoidance responses, manifested as stem and petiole elongation, suppressed branching, and altered petiole angles. Elucidating the molecular underpinnings of shade avoidance remains imperative for rationalizing planting density strategies in crop production. Here, we report that soybean SHADE-REDUCED GENE 1 (GmSRG1) inhibits the stem and petiole growth both in white light and low ratio of Red:Far-red light conditions in soybean. GmSRG1 likely represents a catalytically inactive homolog of xyloglucan endotransglucosylase/hydrolase that lacks the conserved active site. Despite its enzymatic deficiency, it is associated with enhanced xyloglucan-degrading activity and prevents xyloglucan accumulation in soybean. GmBBX17 binds to the GmSRG1 promoter to repress its transcription, whereas GmSTFs (GmSTF1 and GmSTF2) transcriptionally activate GmSRG1. GmBBX17 physically interacts with GmSTFs to antagonistically regulate GmSRG1 expression. Unlike GmSRG1, its close homolog GmXTH23 is associated with increased xyloglucan accumulation and reduced xyloglucan-degrading activity, while GmSRG1 physically interacts with GmXTH23 and counteracts this GmXTH23-associated effect. Our work reveals an integrated regulatory network comprising the GmBBX17-GmSTFs transcriptional module and the GmSRG1-GmXTH23 regulatory module, which collectively govern shade avoidance architecture in soybean.

Glycine max↗

PubMed2025

Water shortage reduces PHYTOCHROME INTERACTING FACTOR 4, 5 and 3 expression and shade avoidance in Arabidopsis.

In agricultural crops, forests and grasslands, water deficit often occurs in the presence of cues from neighbouring vegetation. However, most studies have addressed separately the mechanisms of plant growth responses to these two aspects of the environment. Here we show that transferring Arabidopsis thaliana seedlings to agar containing polyethylene glycol (PEG) to restrict water availability reduces hypocotyl growth responses to shade without simultaneously affecting cotyledon expansion or its response to shade. Hypocotyl growth showed significant triple interaction among water availability, shade and the presence of PHYTOCHROME INTERACTING FACTOR 4 (PIF4), PIF5 and PIF3. Water restriction diminished auxin signalling and the activity of the PIF4, PIF5, PIF3 gene promoters and their transcript levels. The responses of PIF4 expression and hypocotyl growth to PEG were reduced in mutants of its positive morning regulators CIRCADIAN CLOCK ASSOCIATED 1 (CCA1) and LATE ELONGATED HYPOCOTYL (LHY). The CCA1 and LHY gene promoters also reduced their activity in response to PEG. In addition to the changes in PIF4 levels, post-transcriptional processes also contributed to the PIF4 protein response to PEG. Collectively, these results unveil PIFs as a hub that interlinks shade and drought information to control growth.

Arabidopsis↗

PubMed2026

DNA-binding activity of PIF7 links phytochrome B signaling to plant responses to vegetation proximity.

PHYTOCHROME INTERACTING FACTORs (PIFs) are transcription factors that act as central signaling hubs in light-regulated processes. All PIFs contain an active phytochrome B-binding motif and a DNA-binding basic helix-loop-helix domain. In the shade-avoider Arabidopsis thaliana, PIF7 is a major promoter of hypocotyl elongation in response to vegetation proximity, becoming active when released from phytochrome B via its active phytochrome B-binding motif. Here we show that PIF7 promotes seedling elongation in other species, including the shade-avoider tomato and the shade-tolerant Cardamine hirsuta, suggesting that PIF7 has retained some of its key functional domains across diverse plants. Through complementation analyses using PIF7 variants lacking either the active phytochrome B-binding or basic helix-loop-helix domain, we demonstrate that, unlike PIF3, PIF7 versions unable to bind phytochrome B remain active regardless of light conditions, whereas loss of DNA-binding capacity fully disrupts PIF7 function. Our results further suggest that phytochrome B interaction imposes a dual regulatory control over PIF7, modulating both its abundance and its phosphorylation state (ie its ability to bind and regulate target genes).

Phytochrome B↗

PubMed2026

Dynamic shading of chloroplasts for enhanced photosynthetic efficiency.

Coping with high light represents a major challenge for plants in nature. Under high light, 1O2 can induce MBS1 to form a low-dynamic condensate, which can effectively shade chloroplasts to avoid photodamage. This mechanism can be used to support breeding crops for both high photoprotection and high photosynthetic light use efficiency.

Photosynthesis↗

PubMed2026

Orchard netting impacts on biodiversity leading to cascading effects at the ecosystem level.

Agriculture must ensure food production without further compromising the ecosystem functions upon which it depends. Agricultural practices should therefore avoid harming farmland biodiversity, especially of taxa that supply the key ecosystem services (e.g. pollination, pest control and nutrient uptake) that ultimately support crop production. Orchards are among the largest permanent plantations worldwide and are increasingly characterised by the spread of plastic nets used to protect fruits/nuts from either abiotic (anti-hail, anti-rain, shade nets) or biotic (exclusion nets) hazards. Despite having received little attention to date, these nets may impact natural communities, acting both as physical barriers and as drivers of habitat changes to which biota must respond. Species-level responses to netting depend on the organism's ability to enter the netted environment and successfully exploit available resources. Net-mediated ecological filtering and plastic behavioural responses may alter species interactions, leading to cascading ecological impacts that may create species-poorer 'netted communities' with simplified ecological networks. Such changes may erode biological control potential, other ecosystem functions, and overall system stability. We conducted a systematic review on the effects of protection nets on biota, and reported novel empirical evidence on anti-hail nets' impacts on communities of orchard-dwelling birds, flower-visiting insects, and rodents. In total, we identified 48 studies from the literature, however this literature was strongly biased towards apple orchards, western countries, and pest taxa. Net deployment was highly effective in deterring target pest species, in some cases regardless of their original function, as even weather-protection nets limited pest populations. Side effects on non-target taxa were also often reported, such as decreases in pollinators and natural enemies, and/or increases in secondary pests or microbial diseases. However, most assessments largely disregarded non-pest taxa and the broader ecological consequences of netting. The few studies that addressed the effects of nets at the guild/community level, including our empirical study, confirmed that orchard netting resulted in species-poor assemblages, with possible ecosystem-level consequences. We propose that future assessments should pay more attention to the indirect effects of netting on non-target taxa, and on the supply of crop-supporting ecosystem services mediated by wild species occurring in agroecosystems. Due to the trade-offs between these services and net-mediated crop protection, integrated alternatives should be tested to improve the environmental sustainability of food production and biodiversity conservation in farmed landscapes.

Biodiversity↗