Plant, Cell & Environment最新文献

TALE (Three Amino acid Loop Extension) homeodomain transcription factors are key conserved elements in eukaryotic developmental patterning. In plants, this superclass divides into the KNOX and BELL families, which are essential for regulating meristem maintenance, organogenesis, and tissue identity. Recent advances show that TALE proteins are intricately involved in plant reproductive processes, including gametophyte differentiation, embryonic axis formation, and floral organogenesis. They function as molecular scaffolds, integrating spatiotemporal signals and hormonal signaling like auxin, cytokinin, and gibberellin to control phase transitions and reproductive cell fate determination. The lineage-specific expansions and domain rearrangements of TALE genes across bryophytes, gymnosperms, and angiosperms indicate repeated co-option and neofunctionalization throughout land plant evolution. Emerging insights from epigenomics and protein interactomes reveal that TALE complexes modulate cell type-specific transcriptional responses. This review synthesizes current understanding of TALE-mediated regulatory networks during plant reproductive development and presents a conceptual framework for investigating their roles in developmental plasticity and stress-responsive fertility. We also highlight opportunities to utilize TALE-based regulatory modules to develop climate-resilient crops through multi-omics and genome editing approaches. Decoding the reproductive logic embedded in TALE networks offers transformative potential for reprogramming plant development in an era of agricultural and ecological uncertainty.

Tetraploid Thinopyrum elongatum represents a valuable tertiary genetic pool for wheat improvement, harbouring numerous valuable agronomic traits. Our previous study identified Yr4EL, which confers all-stage resistance to stripe rust, was initially characterized from the tetraploid Th. elongatum chromosome (chr) 4E. To further fine-map Yr4EL, we generated 140 chr 4E structural variants using ⁶⁰Co-γ irradiation, ph1b-induced, and double monosomy centromere breakage-fusion methods. All variants were cytogenetically characterized using genomic in situ hybridization and fluorescence in situ hybridization. These variants comprised 90 distinct chr 4E structural variants, including 20 fragment deletions, 14 large segment translocations, 19 whole-arm translocations, 10 chr 4E insertion translocations, and 27 terminal small fragment translocations. A high-resolution chr 4E physical map was constructed using molecular markers, delineated into 15 distinct bins. Subsequently, the diploid Th. elongatum reference genome (ASM1179987v1) enabled the fine-mapping of Yr4EL to a 1.8 Mb interval within the distal chr 4EL. Transcriptomic profiling, evolutionary analysis, and qRT-PCR validation identified five genes that might be the Yr4EL candidate. In addition, we deployed Yr4EL into susceptible common wheat varieties, conferring effective stripe rust resistance without a yield penalty, demonstrating its high potential value for wheat breeding programmes.

Non-photochemical quenching (NPQ) is a vital photoprotective mechanism in plants, facilitating the dissipation of excess excitation energy as heat within photosystem II. Combined over expression photoprotection proteins, violaxanthin de-epoxidase (VDE), photosystem II subunit S protein (PsbS) and zeaxanthin epoxidase (ZEP) can accelerate the dynamics of photoprotection during the transition of leaves from sun to shade. However, not all transgenic plants exhibited increased efficiency of dynamic photosynthesis and growth performance in previous studies. To investigate the impact of Arabidopsis VDE, PsbS and ZEP genes (VPZ) on rice, we generated rice transgenic plants. The VPZ lines showed comparable NPQ induction and relaxation rate to those reported in previous studies, enhancing their photoprotective capacity. Nevertheless, they exhibit growth retardation, decreased photosynthetic capacity and reduced biomass accumulation under different light regimes and field conditions. This negative impact on the VPZ rice lines may be caused by the alterations to photochemical quenching under normal light conditions. Alleviating or eliminating the potential factor might help to enhance the growth and biomass accumulation in the VPZ lines.

Abscisic acid (ABA) receptors (PYR) are essential components of the ABA signalling pathway. This study reported wheat PYR gene, TaPYR10, in modulating plant adaptation to drought stress. TaPYR10 contains conserved PYR motifs and targeted nucleus. TaPYR10 transcripts were upregulated in response to drought stress, attributing to the drought response-associated cis-elements that regulate gene transcription. Using Y-2H, BiFC, Co-IP and in vitro pull-down assays, the study revealed interactions among TaPYR10, PP2C phosphatase member TaPP2C30, SnRK2 kinase member TaSnRK2.10 and transcription factor TaNF-YC1 using specific conserved domains, suggesting that TaPYR10 constitutes a regulatory pathway with these partners (i.e., TaPYR10-TaPP2C30-TaSnRK2.10-TaNF-YC1). TaPYR10, TaSnRK2.10 and TaNF-YC1 positively whereas TaPP2C30 negatively regulated drought adaptation by modulating osmotic stress-associated physiological processes. TaNF-YC1 activated the transcription of a suite of stress-responsive genes, including the S-type anion channel gene TaSLAC1-3, delta-pyrroline-5-carboxylate synthetase (P5CS) gene TaP5CR1, superoxide dismutase (SOD) gene TaSOD4, catalase (CAT) gene TaCAT2 and the PIN-FORMED gene TaPIN6, which contributed to the TaPYR10 regulatory pathway-modulated drought response. TaPYR10 transcripts were positively correlated with yield in a wheat variety panel under drought conditions, with haplotype TaPYR10-Hap1 conferring increased target transcripts and drought tolerance. Overall, our findings provide novel insights into plant drought response mediated by the TaPYR10 signalling pathway.

The cover image is based on the article Decoding Xylem Development in Flowering Plants: Insights From Single-Cell Transcriptomics by Jhong-He Yu et al., https://doi.org/10.1111/pce.70169.

Factors controlling plant photosynthesis and primary production include parameters dictating photosynthetic activity together with export and allocation properties. In fact, phloem loading activity as well as phloem sap redistribution and velocity are considered as important players in plant carbon acquisition. But surprisingly, there is almost no information about how phloem sap properties such as sugar concentration and velocity, are controlled by photosynthetic rate. Here, we carried out gas exchange experiments coupled to isotopic labelling on sunflower leaves to monitor photosynthate export rate when photosynthesis was varied with CO₂ mole fraction. We took advantage of a compartmental isotope model to obtain an experimental estimate of phloem sugar pool size and thus sap concentration and velocity. Phloem sugar concentration was found to increase relatively slowly (from very low values to about 1 mol L^{- 1}) with photosynthesis and export rate, while sap velocity remained in the same order of magnitude (0.2-0.6 mm s^-1). This phenomenon could be explained using a simple one-dimensional model of phloem sap generation and movement suggesting that at fixed photosynthesis, phloem sap was in a steady-state reflecting the balance between xylem-to-phloem and sieve tube hydraulic conductance, turgor pressure and osmotic pressure due to loading. Our study also shows that phloem sap composition was not invariant with photosynthetic conditions but rather, adjusted to leaf export while maintaining sap flow even at very low CO₂.

Lateral root (LR) formation is governed by a complex regulatory network that includes various internal factors such as transcription factors (TFs) and phytohormones, of which ethylene is a key repressor. However, the core TFs that regulate ethylene biosynthesis and LR development remain unknown. Here, we found that the WRKY TF SbWRKY50 was required for LR development in Sorghum bicolour L. Overexpression of SbWRKY50 in sorghum increased the number and length of LRs, whereas both decreased in the CRISPR/Cas9-edited SbWRKY50 mutant. SbWRKY50 positively regulated LR generation by directly repressing several 1-aminocyclopropane-1-carboxylate synthase (ACS) genes. In addition, SbWRKY50 directly interacted with SbBMI1A to facilitate the recruitment of the PRC1 complex and induced H2A ubiquitination (H2Aub) accumulation on SbACS genes, thereby promoting epigenetic silencing and LR formation. The positive role of SbWRKY50 in stay-green and LR formation improves the agronomic traits of sorghum, improving drought tolerance and potentially contributing to increased sorghum yield.

d-limonene is a key monoterpene that contributes to the characteristic aroma of tea (Camellia sinensis) and plays a defensive role against pathogenic infections. However, the regulatory mechanisms underlying its biosynthesis and associated disease resistance remain largely elusive. In this study, d-limonene levels were found to be significantly elevated in pathogen-infected tea leaves, and exogenous application of d-limonene markedly enhanced resistance to gray blight disease. Transcriptomic analysis identified CsTPS5, encoding a terpene synthase, as bening strongly induced upon pathogen challenge. Subcellular localization, in vitro enzyme assays, and in vivo functional verification demonstrated that CsTPS5 catalyzes the conversion of geranyl diphosphate (GPP) into d-limonene. Furthermore, yeast one-hybrid screening, electrophoretic mobility shift assays (EMSA), and dual-luciferase reporter assays revealed that the bHLH transcription factor CsbHLH124 directly binds to the promoter of CsTPS5 and activates its expression. Gene silencing experiments further confirmed that the CsbHLH124-CsTPS5 regulatory module plays a crucial role in promoting d-limonene biosynthesis and suppressing lesion formation caused by Pseudopestalotiopsis camelliae-sinensis (Ps.cs.). These findings elucidate a previously uncharacterized regulatory pathway controlling terpene metabolism and provide a promising molecular framework for enhancing both aroma quality and disease resistance in tea breeding programmes.