Drought stress is one of the most critical threats to crop productivity and global food security. This review addresses the multiple effects of drought on the process of photosynthesis in major food crops. Affecting both light-dependent and light-independent reactions, drought leads to severe damage to photosystems and blocks the electron transport chain. Plants face a CO₂ shortage provoked by stomatal closure, which triggers photorespiration; not only does it reduce carbon fixation efficiency, but it also causes lower overall photosynthetic output. Drought-induced oxidative stress generates reactive oxygen species (ROS) that damage cellular structures, including chloroplasts, further impairing photosynthetic productivity. Plants have evolved a variety of adaptive strategies to alleviate these effects. Non-photochemical quenching (NPQ) mechanisms help dissipate excess light energy as heat, protecting the photosynthetic apparatus under drought conditions. Alternative electron pathways, such as cyclical electron transmission and chloroplast respiration, maintain energy balance and prevent over-reduction of the electron transport chain. Hormones, especially abscisic acid (ABA), ethylene, and cytokinin, modulate stomatal conductance, chlorophyll content, and osmotic adjustment, further increasing the tolerance to drought. Structural adjustments, such as leaf reordering and altered root architecture, also strengthen tolerance. Understanding these complex interactions and adaptive strategies is essential for developing drought-resistant crop varieties and ensuring agricultural sustainability.

In bacteria and chloroplasts, the GTPase filamentous temperature-sensitive Z (FtsZ) is essential for division and polymerizes to form rings that mark the division site. Plants contain two FtsZ subfamilies (FtsZ1 and FtsZ2) with different assembly dynamics. FtsZ1 lacks the C-terminal domain of a typical FtsZ protein. Here, we show that the conserved short motif FtsZ1 Carboxyl-terminus (Z1C) (consisting of the amino acids RRLFF) with weak membrane-binding activity is present at the C-terminus of FtsZ1 in angiosperms. For a polymer-forming protein such as FtsZ, this activity is strong enough for membrane tethering. Arabidopsis thaliana plants with mutated Z1C motifs contained heterogeneously sized chloroplasts and parallel FtsZ rings or long FtsZ filaments, suggesting that the Z1C motif plays an important role in regulating FtsZ ring dynamics. Our findings uncover a type of amphiphilic beta-strand motif with weak membrane-binding activity and point to the importance of this motif for the dynamic regulation of protein complex formation.

Filamentous temperature-sensitive Z (FtsZ) is a tubulin-like GTPase that is highly conserved in bacteria and plants. It polymerizes into a ring at the division site of bacteria and chloroplasts and serves as the scaffold protein of the division complex. While a single FtsZ is present in bacteria and cyanobacteria, there are two subfamilies, FtsZ1 and FtsZ2 in the green lineage, and FtsZA and FtsZB in red algae. In Arabidopsis thaliana, the C-terminal motifs of AtFtsZ1 (Z1C) and AtFtsZ2-1 (Z2C) display distinct functions in the regulation of chloroplast division. Z1C exhibits weak membrane-binding activity, whereas Z2C engages in the interaction with the membrane protein AtARC6. Here, we provide evidence revealing the distinct traits of the C-terminal motifs of FtsZ1 and FtsZ2 throughout the plant evolutionary process. In a range of plant species, the C-terminal motifs of FtsZ1 exhibit diverse membrane-binding properties critical for regulating chloroplast division. In chlorophytes, the C-terminal motifs of FtsZ1 and FtsZ2 exhibit both membrane-binding and protein interaction functions, which are similar to those of cyanobacterial FtsZ and red algal FtsZA. During the transition from algae to land plants, the functions of the C-terminal motifs of FtsZ1 and FtsZ2 exhibit differentiation. FtsZ1 lost the function of interacting with ARC6 in land plants, and the membrane-binding activity of FtsZ2 was lost in ferns. Our findings reveal the functional differentiation of the C-terminal motifs of FtsZs during plant evolution, which is critical for chloroplast division.

Peonies (Paeonia spp.) are renowned for their beautiful ornamental flowers and significant cultural, medicinal, and economic values. Based on growth habit, peonies are categorized into herbaceous and tree peonies. Viral infections in peonies, historically referred to as “peony ringspot” or “peony mosaic” diseases, have been reported worldwide over decades. Infections symptoms typically include leaf discoloration and diminished flowering, substantially reducing both ornamental and commercial quality. In severe cases, viral diseases can cause stunted plant growth and impaired flowering, directly affecting peony cultivation and the floriculture profitability. This review systematically summarizes the current research on key viral diseases in peonies, addressing disease classification, symptomatology, causative viruses, pathogenesis, molecular virus–host interactions, and contemporary approaches for prevention and management. The insights provided in this review offer a theoretical foundation and practical guidelines to facilitate effective control of peony viral diseases, potentially promoting sustainable development within the peony industry.

Tree peony (Paeonia suffruticosa Andr.) is a traditional ornamental plant of high economic and cultural value, but its flower longevity is often limited by petal water loss. Cuticular wax serves as an essential barrier against non-stomatal water loss, and the AP2/EREBP (APETALA2/Ethylene-Responsive Element Binding Protein) transcription factor family is known to regulate wax biosynthesis. However, little information is available on the roles of AP2/EREBP genes in petal cuticle formation in tree peony. In this study, we performed transcriptome sequencing on petals of the tree peony cultivar ‘Bai Wang Shi Zi’ at three developmental stages (early, middle, and late). Using the assembled transcriptomic data, we identified 29 high-confidence AP2/EREBP family members, which were phylogenetically classified into AP2, ERF, and DREB subfamilies. Expression profiling revealed that 18 of these genes exhibited stage-specific expression patterns during petal development. Among them, two homologs of Arabidopsis SHN1 (SHINE 1) and WRI3 (WRINKLED 3), designated PsSHN1 and PsWRI3, showed peak expression at the middle stage. By co-expression analysis and phylogenetic comparison, three downstream candidate genes were identified and named PsCER2, PsKAS1, and PsLTPG1, based on their homology with known wax-related genes. Dual-luciferase reporter assays indicated that PsSHN1 and PsWRI3 can activate the promoters of PsCER2, PsKAS1, and PsLTPG1, suggesting a possible cooperative regulation of cuticle formation. Collectively, our findings provide promising candidate genes for prolonging floral lifespan by improving petal cuticular wax accumulation, and lay a preliminary foundation for molecular breeding and quality improvement of tree peony and other ornamental flowers.

The FAR-RED IMPAIRED RESPONSE 1 (FAR1) and FAR-RED ELONGATED HYPOCOTYL 3 (FHY3) transcription factors, together with other members of the FAR1-RELATED SEQUENCE (FRS) and FRS-RELATED FACTOR (FRF) families, represent a striking example of transposable element domestication in plants. Derived from ancient Mutator-like element (MULE) transposases, these proteins have been repurposed as transcriptional regulators throughout the plant kingdom. FHY3 and FAR1 were first identified in Arabidopsis thaliana as positive regulators of phytochrome A (phyA) signaling. They participate in the coordination of light signaling with the circadian clock, chlorophyll biosynthesis, hormone pathways, stress responses, flowering time, shoot branching, leaf senescence, seed dormancy, and phosphate homeostasis. At the molecular level, FHY3 and FAR1 regulate gene expression mainly by binding to the conserved FHY3/FAR1-binding site, FBS, with the sequence CACGCGC, in the promoters of target genes. They also act through protein interactions with key signaling regulators, including HY5, PIFs, EIN3, TOC1, and SPL transcription factors. In this review, we summarize the molecular basis of FHY3/FAR1 gene family function, discuss the roles and mutant phenotypes of characterized family members, and highlight recent advances from other plant species beyond Arabidopsis. Collectively, this gene family illustrates how domesticated transposase-derived proteins have evolved into key regulators of plant development and environmental adaptation.