Journal of Integrative Plant Biology最新文献

Deciphering how environmental factors and epigenetic modifications regulate key metabolic pathways provides novel insights for crop breeding and optimization of cultivation conditions. Zhang et al. (pages 383–405) revealed that light signal-mediated epigenetic regulation affects fruit ripening and quality in tomato. As shown on the cover, light signals act via the photoreceptors phytochrome B₂ (phyB₂), and cryptochrome 1a (CRY1a), which are represented as lights carried by helicopters, to induce expression of the DNA demethylase gene DEMETERLIKE2 (DML2). These photoreceptors act through the transcription factor ELONGATED HYPOCOTYL5 (HY5), which is represented as a person atop a tomato shoot. The inset represents DML2-mediated epigenetic changes to DNA methylation. These changes regulate ripening-related genes and thus accelerate fruit ripening and enhance fruit quality.

Tension wood (TW), a type of reaction wood that develops in angiosperm trees in response to gravistimulation, serves as an ideal model for investigating the regulatory mechanisms underlying xylem cell differentiation and cell wall deposition. The initial biological signals that induce the formation of reaction wood in response to gravitational stimuli remain poorly understood. In this study, we utilized pharmacological and genetic approaches to modulate Ca²⁺ levels in hybrid white poplar (Populus alba × P. glandulosa) and examine the role of calcium signaling during the early stages of gravitropic responses. Our findings revealed differential cytosolic Ca²⁺ signal distribution in gravistimulated stems during the early phase of gravity induction, characterized by lower Ca²⁺ levels on the upper side (where TW forms) and higher Ca²⁺ levels on the lower side (where opposite wood forms). Consistent with this hypothesis, plants treated with LaCl₃ and those with genetically disrupted calcium channels (PagGLR3.3 knockout using the CRISPR/Cas9 system) showed reduced Ca²⁺ signals and developed characteristic TW features. These results suggest that decreased Ca²⁺ levels induce the formation of TW. Furthermore, PagGLR3.3 knockout plants with TW-like stems displayed diminished sensitivity to gravistimulation. Transcriptomic analysis revealed that the knockout of PagGLR3.3 resulted in the upregulation of genes associated with TW formation and reactive oxygen species (ROS) production. Notably, superoxide anion (O₂ ^·-) levels were significantly elevated in the cambium zone of stems subjected to gravistimulation, LaCl₃ treatment, or PagGLR3.3 knockout, indicating that reduced Ca²⁺ levels promote TW formation through increased O₂ ^·- accumulation. This study offers novel insights into the critical role of Ca²⁺ in gravitropism and TW induction in poplar.

This commentary on Wang et al. (2025) and Phan et al. (2025) highlights previously undiscovered Xanthomonas pathways for nutrition acquisition, explains how Xanthomonas bacteria hijack host molecular machinery through their effector proteins, and discusses how these studies can be used to develop new disease resistance mechanisms.

While plant salicylic acid (SA) signaling via NPR1-PR1 is well-characterized in pathogen resistance, its role against piercing-sucking insects remains unclear in rice. Here, we demonstrate that leafhopper infestation in rice induces SA-mediated resistance, which defends against insect infestation via pathogenesis-related protein OsPR1a. However, prolonged infestation triggers autophagy-dependent degradation of OsPR1a through its interaction with OsATG8b, fine-tuning immunity to prevent excessive defense activation. Strikingly, this autophagy-mediated OsPR1a degradation represents a conserved regulatory mechanism in rice during brown planthopper infestation. A rice rhabdovirus in leafhopper vectors secretes glycoprotein on virion envelopes to rice phloem, where it binds OsATG6b and OsPR1a to enhance autophagic OsPR1a turnover, ultimately facilitating insect vector feeding and viral transmission by leafhopper vectors. Our work reveals an adaptive mechanism by which a vector-borne virus hijacks plant autophagy to evade SA immunity, highlighting OsPR1a as a critical convergence point in plant-insect-virus interactions.

This commentary highlights emerging strategies for efficient plant regeneration through control of morphogenic regulators that govern cell identity. Synthetic expression systems, enabled by high-throughput discovery platforms, can direct plant cells to form new tissues or organs, opening new possibilities for efficient genetic engineering of agronomically important crops.

Global warming imposes a major threat to plant survival by disrupting growth homeostasis, yet plants adapt to elevated temperatures through thermomorphogenesis. Although auxin signaling is known to orchestrate these adaptive responses, how temperature perception is integrated with auxin remains poorly understood. Here, we identify the CrRLK1L-family receptor kinase FERONIA (FER) as a central regulator of thermomorphogenesis in Arabidopsis thaliana. Under warm-temperature conditions, FER undergoes proteolytic cleavage, releasing its cytosolic domain FER^CD, which translocates into the nucleus via an importin-dependent pathway. Once in the nucleus, FER^CD phosphorylates the non-canonical AUX/IAA protein IAA29, thereby relieving its inhibition of ARF19 and promoting hypocotyl elongation. Transcriptomic analyses further reveal that FER and ARF19 co-regulate thermo-inducible genes involved in auxin signaling and cell wall remodeling. Together, these findings uncover the mechanism by which FER integrates thermal cues through proteolytic activation and phosphorylation-dependent modulation of auxin signaling, establishing a new paradigm for receptor kinase-mediated environmental adaptation in plants.

Soybean is a major crop that produces high-quality seed oil for global consumption. However, the regulatory mechanisms underlying seed oil content remain poorly understood. In this study, GmGT-2F, a trihelix transcription factor, was identified as a positive regulator of seed oil content. It was observed that GmGT-2F expression gradually increased during seed development. Furthermore, GmGT-2F overexpression elevated seed oil content and increased the proportion of oleic and linoleic acids in fatty acid composition. However, knocking out GmGT-2F improved seed protein content and seed size. We demonstrated that GmGT-2F binds to the GmAGAL promoter and activates its transcription. Moreover, knockout of GmAGAL and GmGT-2F/GmAGAL reduced α-galactosidase activity and decreased seed oil content. The metabolomic and seed sucrose content analyses of the gmagal and wild-type (WT) plants showed that GmGT-2F affects the transcription of GmAGAL to regulate the activity of α-galactosidase and may control the oil content by influencing the generation and distribution of sucrose in the seed. In addition, GmCYP2 interacts with GmGT-2F, reducing its promoter-binding activity and inhibiting GmAGAL transcription. Haplotype diversity analyses of GmGT-2F, GmCYP2, and GmAGAL revealed combinations associated with increased oil or protein content. This study elucidates the regulatory mechanism by which GmGT-2F regulates seed oil content, expands understanding of trihelix transcription factor function in seed quality trait regulation, and provides new insights for high-quality soybean breeding.

CRISPR/Cas12i3 belongs to the type V-I Cas system, characterized by its smaller protein size and less restricted canonical "TTN" protospacer adjacent motif. Developments of Cas12i3-mediated base editing systems for either C-to-T or A-to-G transitions will expand the editing scope and enrich the plant base editing toolkits for crop improvement. However, while the Cas12i3-based cytosine base editor (CBE) only shows very low editing efficiency in plants, its adenine base editor (ABE) has not been documented as yet. Here, we engineered a series of Cas12i3 (5M)-based CBEs (V0-V5) and ABEs (V0-V5) by fusing a deactivated dCas12i3 (5M) with a transactivation module VP64, a single-stranded DNA-binding domain Rad51, or a double-stranded DNA-binding domain HMG-D, or in combinations, and systemically evaluated their performance in rice protoplasts. Our results demonstrated that synergistic combinations of both VP64 and HMG-D outperformed other architectures and significantly boosted the efficiencies of Cas12i3 (5M)-based CBE and ABE for C-to-T and A-to-G base editing and expanded the editing window. In stable lines, in comparison to the non-fusion control, the optimized Cas12i3 (5M)-based CBE-V5 and ABE-V5 enabled up to 4.78- and 3.35-fold higher editing efficiencies, with the maximum C-to-T and A-to-G efficiencies reaching 32.35% and 38.24%, respectively, and a higher proportion of homozygous mutants in the T₀ generation. Furthermore, we generated herbicide-resistant rice germplasm by using CBE-V5 and ABE-V5, demonstrating their potential for precision breeding in crops. Together, here, we report novel Cas12i3 (5M)-based CBE and ABE that substantially enrich base editing toolkits for improvement of rice and potentially other crops.

Small G proteins, functioning as monomeric GTPases, are critical molecular switches that regulate diverse processes in plants. However, little is known about their protein homeostasis during immune responses. Here, we demonstrate that OsRab11C1, encoding a Rab-type GTPase, is transcriptionally upregulated upon Magnaporthe oryzae infection. Strikingly, loss of OsRab11C1 enhances rice blast resistance, concomitant with increased defense gene expression, MAPK activation, and ROS burst. Mechanistically, we identify the E3 ubiquitin ligase EL5 as an interactor that ubiquitinates and targets OsRab11C1 for degradation via the 26S proteasome. Consistently, EL5 acts upstream of OsRab11C1 and positively regulates rice immunity. Further analysis reveals that OsRab11C1 interacts with and stabilizes mitogen-activated protein kinase kinase OsMKK6, thereby facilitating its autophosphorylation activity. In return, OsMKK6 acts as a negative regulator of rice programmed cell death and immunity. Collectively, our findings unveil a dynamic EL5-OsRab11C1-OsMKK6 signaling module that orchestrates rice immunity against pathogen invasion.