Plant, Cell & Environment最新文献

Terpenoids, a diverse class metabolites regulate plant growth and development. Geranylgeranyl pyrophosphate synthase (GGPPS) mediates GGPP biosynthesis through two pathways: the mevalonate (MVA) and the methylerythritol phosphate (MEP). GGPP serves as a common precursor for chlorophyll, carotenoids, and other terpenoids. We assayed the enzymatic activity of GGPPS isozymes in upland cotton and identified those with high enzymatic activity. Silencing of GhGGPPS10/23 produced leaf variegation and decreased plant height. Transcriptomic and metabolomic analyses revealed that downregulation of GhGGPPS10/23 influenced the expression patterns of genes involved in chlorophyll and carotenoid biosynthesis pathways, as well as altered metabolic fluxes. Overexpression of GhGGPPS10 and GhGGPPS23 produced significantly improved biomass and photosynthetic efficiency along with increased levels of key metabolites. Taken together, our findings indicate that GhGGPPS10/23 are involved in regulating multiple developmental processes associated with agronomically important traits.

With global climate change, waterlogging is occurring with increasing frequency. Waterlogging is an important abiotic stress, which restricts plants growth and development, significantly reduces crop yield and seriously threatens the safety and sustainable development of agricultural production. Therefore, understanding the mechanisms of plant response to waterlogging is essential for the food security. Here, we review the damage of waterlogging, the physiological and morphological adaptation of plants response to waterlogging, summarize the relevant genes and molecular mechanism of plant waterlogging tolerance, and look forward to the current challenges and future directions of cultivating waterlogging-tolerant varieties. This review provides a scientific basis and research direction for deepening the understanding of plant waterlogging tolerance mechanisms.

Plants activate induced defences through the recognition of molecular patterns. Like pathogen-associated molecular patterns, herbivore-associated molecular patterns (HAMPs) can be recognised by cell surface pattern recognition receptors, leading to defensive transcriptional changes in host plants. Herbivore-induced defensive outputs are regulated by the circadian clock, but the underlying molecular mechanisms remain unknown. To investigate how the plant circadian clock regulates transcriptional reprogramming of a specific HAMP-induced pathway, we characterised the daytime and nighttime transcriptional response to the caterpillar-derived HAMP peptide In11 in the legume crop cowpea (Vigna unguiculata). Using diel and free-running conditions, we found that daytime In11 elicitation resulted in stronger late-induced gene expression than nighttime. Plants with a conditional arrhythmic phenotype in constant light conditions lost time-of-day gated responses to In11 treatment, and this was associated with arrhythmic expression of circadian clock core transcription factor Late Elongated Hypocotyl VuLHY1 and VuLHY2. Reporter assays with VuLHY homologues indicated that they interact with the promoter of daytime In11-induced Kunitz Trypsin Inhibitor (VuKTI) via a canonical and a polymorphic CCA1/LHY binding site (CBS), consistent with a mechanism of direct regulation by circadian clock transcription factors. This study improves our understanding of the time-dependent mechanisms that regulate herbivore-induced gene expression.

Insect herbivory generates not only tissue loss but also a suite of biophysical and chemical cues that plants must detect and interpret. To cope with these challenges, plants have evolved specialised structures and molecular mechanisms that perceive mechanical inputs and translate them into coordinated defence responses. This review summarises the concept of mechanostimulation during insect feeding, with a focus on how plants recognise mechanical cues and integrate them into broader defence signalling networks. We outline the types of stimuli generated during herbivory, the morphological and molecular sensors involved in mechanoperception, and the electrical signalling processes that mediate intra- and inter-cellular communication of long-distance signal transmission, for which the vascular system, particularly the phloem and xylem, emerges as a critical conduit. We further discuss how mechanostimulation interfaces with hormonal pathways and transcriptional regulation, ultimately activating defence genes. This framework is further extended to non-vascular plants such as bryophytes, where mechanosensing and defence occur in the absence of vascular tissues, shedding light on how these strategies originated and evolved in early land plants. Collectively, these insights provide a comprehensive framework for understanding how mechanostimulation shapes plant defence and offers avenues for future research in enhancing crop resilience.

Citrus fruit de-greening, a critical process for quality and marketability, is governed by chlorophyll degradation, yet its regulatory mechanisms remain poorly understood. Here, we identify FcrNAC22, a NAC transcription factor (TF) in kumquat (Fortunella crassifolia), as a pivotal regulator of chlorophyll catabolism activated in response to de-greening cues. FcrNAC22 functions as a transcriptional activator induced by red light, abscisic acid (ABA), and ethephon, with both its mRNA and protein levels peaking at the fruit colour-breaker stage. The overexpression of FcrNAC22 in Nicotiana benthamiana leaves, tomato (Solanum esculentum), and kumquat fruits expedited chlorophyll breakdown and upregulated the expression of chlorophyll catabolic genes (CCGs). In contrast, the interference with FcrNAC22 expression in kumquat fruits impeded chlorophyll degradation and suppressed the transcription of CCGs. Protein-DNA interaction assays verified that FcrNAC22 directly binds to and activates the promoters of chloroplast-localized STAY-GREEN (FcrSGR), chlorophyllase (FcrCLH), pheophytinase (FcrPPH), pheophorbide a oxygenase (FcrPAO), and NON-YELLOW COLORING1 (FcrNYC1), which explains the de-greening phenotypes witnessed in the aforementioned transgenic FcrNAC22 lines. These findings not only reveal FcrNAC22 as a crucial integrator of environmental and developmental signals, but also provide a theoretical basis for manipulating fruit de-greening in citrus and related species.