New Phytologist最新文献

Aboveground and belowground attributes of terrestrial ecosystems interact to shape carbon (C) cycling. However, plants and soil organisms are usually studied separately, leading to a knowledge gap regarding their coordinated contributions to ecosystem C cycling. We explored whether integrated consideration of plant and nematode traits better explained soil organic C (SOC) dynamics than plant or nematode traits considered separately. Our study system was a space-for-time natural restoration chronosequence following agricultural abandonment in a subtropical region, with pioneer, early, mid and climax stages. We identified an integrated fast-slow trait spectrum encompassing plants and nematodes, demonstrating coordinated shifts from fast strategies in the pioneer stage to slow strategies in the climax stage, corresponding to enhanced SOC dynamics. Joint consideration of plant and nematode traits explained more variation in SOC than by either group alone. Structural equation modeling revealed that the integrated fast-slow trait spectrum influenced SOC through its regulation of microbial traits, including microbial C use efficiency and microbial biomass. Our findings confirm the pivotal role of plant-nematode trait coordination in modulating ecosystem C cycling and highlight the value of incorporating belowground traits into biogeochemical cycling under global change scenarios.

To identify efficient salt-tolerant genes is beneficial for coping with the penalty of salt stress on crop yield. Reversible conjugation (sumoylation and desumoylation) of Small Ubiquitin-Like Modifier (SUMO) is a crucial kind of protein modifications, but its roles in the response to salt and other abiotic stress are not well addressed. Here, we identify salt-tolerant SUMO protease gene TaDSU for desumoylation from wheat, and analyze its mechanism in salt tolerance and evaluate its role in yield in saline-alkaline fields. TaDSU overexpression enhances salt tolerance of wheat. TaDSU overexpressors have lower Na⁺ but higher K⁺ contents and consequently higher K⁺ : Na⁺ ratios than the wild-type under salt stress. TaDSU interacts with transcriptional factor MYC2, reduces the sumoylation level of SUMO1-conjugated MYC2, and promotes its transcription activity. MYC2 binds to the promoter of TaDSU and elevates its expression. TaDSU overexpression enhances grain yield of wheat in the saline soil without growth penalty in the normal field. Especially, TaDSU ectopic expression also enhances salt tolerance of Arabidopsis thaliana, showing this SUMO protease allele has the inter-species role in the adaptation to salt stress. Thus, TaDSU is an efficient candidate gene for molecular breeding of salt-tolerant crops.

Cuscuta campestris, a stem parasitic plant, has served as a valuable model plant for the exploration of plant-plant interactions and molecular trafficking. However, a major barrier to C. campestris research is that a method to generate stable transgenic plants has not yet been developed. Here, we describe the development of a Cuscuta transformation protocol using various reporter genes (GFP, GUS, or RUBY) and morphogenic genes (CcWUS2 and CcGRF/GIF), leading to a robust protocol for Agrobacterium-mediated C. campestris transformation. The stably transformed and regenerated RUBY C. campestris plants produced haustoria, the signature organ of parasitic plants, and these were functional in forming host attachments. The locations of T-DNA integration in the parasite genome were confirmed through TAIL-PCR. Transformed C. campestris also produced flowers and viable transgenic seeds exhibiting betalain pigment, providing proof of germline transmission of the RUBY transgene. Furthermore, RUBY is not only a useful selectable marker for the Agrobacterium-mediated transformation, but may also provide insight into the movement of molecules from C. campestris to the host during parasitism. Thus, the protocol for transformation of C. campestris reported here overcomes a major obstacle to Cuscuta research and opens new possibilities for studying parasitic plants and their interactions with hosts.

Functional differences between native and exotic species, estimated when species are grown alone or in mixtures, are often used to predict the invasion risk of exotic species. However, it remains elusive whether the functional differences estimated by the two methods and their ability to predict species invasiveness (e.g. high abundance) are consistent. We compiled data from two common garden experiments, in which specific leaf area, height, and aboveground biomass of 64 common native and exotic invasive species in China were estimated when grown individually (pot) or in mixtures (field). Exotic species accumulated higher aboveground biomass than natives, but only when grown in field mixtures. Moreover, aboveground biomass and functional distinctiveness estimated in mixtures were more predictive of species persistence and relative abundance in the field mixtures in the second year than those estimated when grown alone. These findings suggest that assessing species traits while grown alone may underestimate the competitive advantage for some exotic species, highlighting the importance of trait-by-environment interactions in shaping species invasion. Therefore, we propose that integrating multi-site or multi-year field surveys and manipulative experiments is required to best identify the key trait(s) and environment(s) that interactively shape species invasion and community dynamics.

Genome editing is a revolution in biotechnology for crop improvement with the final product lacking transgenes. However, most derived traits have been generated through edits that create gene knockouts. Our study pioneers a novel approach, utilizing gene editing to enhance gene expression by eliminating transcriptional repressor binding motifs. Building upon our prior research demonstrating the protein-boosting effects of the transcription factor NF-YC4, we identified conserved motifs targeted by RAV and WRKY repressors in the NF-YC4 promoters from rice (Oryza sativa) and soybean (Glycine max). Leveraging CRISPR/Cas9 technology, we deleted these motifs, resulting in reduced repressor binding and increased NF-YC4 expression. This strategy led to increased protein content and reduced carbohydrate levels in the edited rice and soybean plants, with rice exhibiting up to a 68% increase in leaf protein and a 17% increase in seed protein, and soybean showing up to a 25% increase in leaf protein and an 11% increase in seed protein. Our findings provide a blueprint for enhancing gene expression through precise genomic deletions in noncoding sequences, promising improved agricultural productivity and nutritional quality.

Although elevated ambient temperature causes many effects on plant growth and development, the mechanisms of plant high-ambient temperature sensing remain unknown. In this study, we show that GLYCOGEN SYNTHASE KINASE 3s (GSK3s) negatively regulate high-ambient temperature response and oligomerize upon high-temperature treatment. We demonstrate that GSK3 kinase BIN2 specifically interacts with the high-temperature sensor phytochrome B (phyB) but not the high-temperature sensor EARLY FLOWER 3 (ELF3) to phosphorylate and promote phyB photobody formation. Furthermore, we show that phosphorylation of phyB by GSK3s promotes its interaction with ELF3. Subsequently, we find that ELF3 recruits the phyB photobody facilitator HEMERA (HMR) to promote its association with phyB. Taken together, our data reveal a mechanism that GSK3s promote the phyB-ELF3-HMR complex formation in regulating plant thermomorphogenesis.

Epiphytes and their associated biota are increasingly recognized as contributing to biodiversity and to filling critical ecosystem functions in world forests. However, the attributes that have made them successful in canopy environments also make them vulnerable to natural and human-induced disturbances. Drawing upon ecological frameworks to understand disturbance, I categorized and synthesized the drivers and the consequences of disturbances on epiphytic materials. Across all impacts, disturbance agents were significantly more likely to lead to negative, rather than positive, effects in both tropical and temperate locales. Significantly more studies reported negative effects on abundance, diversity, community composition and connectivity, but some studies showed that disturbances enhanced these attributes. Although particular disturbance agents did not differently influence individual consequences, they explained a significant portion of variation in aggregated totals. Surprisingly, relative to human disturbances, natural disturbances were more likely to lead to negative effects. Many studies provided recommendations for effective societal responses to mitigate negative impacts, such as retaining large, old trees in forestry operations, patch-clearing for epiphyte harvest, maximizing forest fragment size, using epiphytes as bioindicators of disturbance, and applying principles of community forestry to land management. Future actions should also include communication of these results to policymakers and land managers.