Acta Physiologiae Plantarum最新文献

The influence of light intensity, including 100% of natural light (L100), 40% of natural light (L40) and 10% of natural light (L10), on the photosynthesis and chlorophyll fluorescence parameters of the rare and endangered plant Emmenopterys henryi oliv. based on transcriptomic and metabolomic analysis were investigated. Results showed that the net photosynthesis rate (P_n) under L40 was higher than that under L100 or L10, which was coincident with higher Fv/Fm, Fv/Fo, qP, NPQ, Y(II), Y(NPQ) and rETR(Ⅱ) but lower Y(NO) under L40 than those under L100 or L10. The common mapping pathways of differentially expressed genes (DEGs) and differentially accumulated metabolites (DAMs) relative to photosynthesis were carbon fixation in photosynthetic organisms and porphyrin and chlorophyll metabolism. Coexpression network analysis showed that the common transcription factors involved in photosynthesis pathway, photosynthesis antenna proteins, carbon fixation in photosynthetic organisms, porphyrin and chlorophyll and carotenoid biosynthesis, such as ERF5, ERF17, ERF16, bHLH100, COL5, DOF12, HHO3, RADL1, MYB17, NAC90, WRK70, WRK29, WRK40, correlated significantly with over 92% of DEGs encoding key enzymes in C₃, C₄ and CAM pathways, and photosynthesis reaction center subunits, and photosynthethic electron transport-related proteins, and F-type ATPase subunits, and light-harvesting complex chlorophyll a/b binding proteins, and key enzymes in chlorophyll and carotenoid biosynthesis under shade. Further research on the common transcription factors will contribute to demonstrating the accommodation mechanism of photosynthesis to low light in E. henryi.

Mentha Species are well known for their valuable essential oils. Limonene synthase is a key enzyme in the monoterpene biosynthesis pathway of mint. In this study, qRT-PCR analysis was conducted on various tissues and treatments of Mentha canadensis to reveal the expression levels and expression response patterns of limonene synthase (McLS) gene. The results demonstrated that McLS was highly expressed in young leaves and was induced by light, abscisic acid (ABA), methyl jasmonate (MeJA), NaCl, and mannitol treatments. The (-)-limonene synthase promoter (proMcLS) was isolated and its cis elements were analyzed. The upstream region contains several cis-acting elements, including core motifs such as the TATA box and CAAT box, light-responsive motifs, ABA- and MeJA-responsive motifs, and guard cell-specific cis elements. Transcriptional fusion of the proMcLS to the gusA reporter gene was conducted in N. tabacum via Agrobacterium-mediated transformation. Transgenic T0 lines displayed β-glucuronidase histochemical staining activity in short glandular trichomes and the stigma of flowers. No signal was detected in tall glandular trichomes or stomatal guard cells, however, T1 lines displayed β-glucuronidase activity in both short glandular trichomes and stomatal guard cells. Transcription factor families predicted to the McLS promoter were predicted using PlantPAN 3.0, and transcription factors co-expressed with McLS under various light treatments were identified. These findings describe a tissue-specific promoter that may be utilized for future metabolic engineering in plants.

The chloroplast genome has a high degree of conservation and a slower evolutionary rate. Studying the codon usage bias (CUB) of the chloroplast genome can clarify the efficiency of gene expression, explore the factors that influence the formation of CUB, and determine the process of plant systematic evolution and species evolution. This study analyzed the codon usage bias of chloroplast gene CDS sequences of 27 Ardisia species, including Ardisia japonica, A. mamillata, A. lindleyana, A. pedalis, and A. merrillii, etc. The analysis results show that the condon usage bias of 27 Ardisia species genus is similar, and their genetic sequences are major in A/T bases, with the third base of codon mainly ending in A/T. The average GC content of the CDS sequences of chloroplast gene in 27 species is 37.34%-38.39%, none of which exceeds 50%. The effective number of codon (ENC) for each gene in the leaf chloroplast genomes of 27 species of Ardisia ranges from 37.16 to 57.63, which are all significantly greater than 35, indicating that the codon usage bias in the chloroplast genomes of these 27 species is relatively weak. The ENC-plot, PR2-plot, and neutral plot analysis show that the codon usage bias in 27 Ardisia species is formed by the joint action of natural selection, base mutation, and other factors, with natural selection playing a dominant role. Through the analysis of relative synonymous codon usage (RSCU), 28 high-frequency codons with A/T ending and 28 low-frequency codons with G/C ending were found. Based on the RSCU and △RSCU values, the study finally identified 5 optimal codons, including ACA (threonine), UAU (tyrosine), CAU (histidine), AGA (arginine), and GGA (glycine). The above results may provide reference for the systematic evolution of Ardisia genus plants and subsequent exogenous gene improvement of chloroplast genomes.

Salinity stress poses a major constraint to turmeric (Curcuma longa L.) production by reducing curcuminoid yield, a key determinant of its medicinal and commercial value. Although salinity is a well-recognized challenge for crop productivity, the understanding of turmeric’s biochemical and molecular responses under salinity stress is still emerging, providing opportunities to clarify their roles in stress adaptation. This study examined the effects of graded salinity levels (50, 100, and 150 mM NaCl) compared with a 0 mM NaCl control on turmeric, focusing on biochemical changes, antioxidant responses, curcuminoid accumulation, and expression of curcumin biosynthetic genes. Correlations among phenolic content, phenylalanine ammonia-lyase (PAL) activity, total curcuminoids, and gene expression were analyzed to define their contribution to salinity tolerance. Salinity reduced chlorophyll content and increased oxidative damage, along with a marked decline in curcuminoid accumulation. Expression analysis revealed downregulation of diketide-CoA synthase (DCS) and Curcumin synthase 2 (CURS2), while PAL, Curcumin synthase 1 (CURS1), and Curcumin synthase 3 (CURS3) were upregulated. PAL enzyme activity and gene expression correlated positively with phenolics but negatively with curcuminoids, indicating a metabolic shift in phenylpropanoid flux. Despite reduced curcuminoids, turmeric accumulated osmolytes and phenolics and enhanced antioxidant enzyme activities, mitigating oxidative stress. Tissue-specific responses showed rhizomes had stronger antioxidant defenses and reactive oxygen species scavenging, whereas leaves were more susceptible to H₂O₂ accumulation and lipid peroxidation, highlighting the rhizome’s protective role. Overall, salinity modulates curcuminoid biosynthesis via gene expression and metabolite allocation, while antioxidant and osmolyte-mediated defenses support stress tolerance, providing insights to optimize curcumin yield under salt stress.

The growth of Larix species has been improved by hybridization, while the hybrid with salt-intolerant species may not be useful for afforestation in saline soil. This study evaluated the relationship between growth responses to salt stress and root functional traits in seedlings of L. gmelinii var. japonica, L. kaempferi, and their hybrid (L. gmelinii var. japonica × L. kaempferi). In a greenhouse, two-year-old seedlings were cultivated with 70 mM of NaCl loading. Roots were divided into tap roots, lignified woody lateral roots, and nonlignified feeder lateral roots. The dry mass, total length and total area and Na concentration of each root were evaluated. The total dry mass of hybrid larch was higher than L. gmelinii regardless of salt stress. The total dry mass and total length of a tap root was suppressed in L. kaempferi by NaCl loading, but not in the other two species. These results demonstrated that the variation in salt tolerance was associated with the vertical distribution of root growth. While Na concentration in primary roots was increased in L. kaempferi and hybrid larch under NaCl loading, the dry mass of primary roots was reduced only in L. kaempferi. In L. gmelinii, dry mass in a tap root and secondary roots were not decreased with the highest Na concentration, indicating the tolerance to Na toxicity accumulated in these roots. Hybrid larch showed no growth suppression with increasing Na concentration in primary roots, suggesting that its superior salt tolerance would be inherited from the mother parent.

Zinc (Zn) is a naturally occurring element found in soil within terrestrial ecosystems, and it plays a vital role in plant growth. However, elevated levels of Zn can lead to various physiological and biochemical changes in plants, potentially impeding their growth and productivity. Growing environmental concerns, along with the delicate balance between zinc’s essential benefits and its toxicity, have prompted increased attention from the scientific community regarding its impact on plants and its significance for agricultural sustainability. This review focuses on the latest findings related to the physiological and biochemical processes influenced by high Zn levels, as well as the mechanisms of Zn uptake and transport in the rhizosphere under elevated zinc conditions. The article compiles the mechanisms by which plants absorb, use, and react to Zn. This review article also explains why some plants can not only survive but thrive in high Zn conditions, while excessive Zn levels can still be harmful. By elucidating the intricate interplay between plants and Zn, this review provides insights for future research directions and practical applications to promote sustainable agriculture and environmental health. Moreover, it covers a wide range of issues, such as physiological reactions, molecular mechanisms and ecological implications, to enlighten researchers in environmental science, agriculture and other relevant fields.

Acidic soils are characterized by the co-occurrence of phytotoxic concentrations of aluminum (Al³⁺) and iron (Fe²⁺/Fe³⁺); however, the interactive effects of these elements within plants and the root environment remain poorly understood. In this study, Amaranthus retroflexus, an Al-accumulating species, was grown hydroponically at pH 4.0 in Al-free (–Al) control or treated with two levels of Al (50 µM, and 400 µM), in combination with either no Fe (–Fe), adequate Fe (20 µM Fe), or excess Fe (100 µM Fe). Leaf chlorosis was induced by Al in Fe-sufficient plants and intensified under Fe deficiency, coinciding with elevated ferric chelate reductase (FRO) activity in roots while Al reduced FRO activity under excess Fe supply. The leaf contents of phenolics and betacyanin increased with rising Al and Fe levels, peaking under the combined application of high Al and excess Fe. Both Fe deficiency and Fe toxicity stimulated the exudation of phenolics and organic acids. Citrate was the predominant carboxylate exuded by Al-free plants, whereas oxalate became dominant under high Al exposure. Aluminum and Fe treatments both reduced foliar accumulation of the other element, with indirect evidence suggesting that Al limits Fe mobility and bioavailability in leaf tissues. These findings demonstrate that A. retroflexus activates internal and external detoxification mechanisms in response to combined Al and Fe toxicity, highlighting a coordinated adaptive strategy for survival in acid soil environments.

CRISPR/Cas9 technology has revolutionized plant science as a precise and efficient genome-editing tool. By enabling targeted modifications in specific genes and genomic regions, it has accelerated functional genomics and facilitated the identification of genes associated with complex agronomic traits such as drought tolerance, pest resistance, and improved nutritional content. Compared with traditional approaches, CRISPR/Cas9 provides rapid functional validation through targeted mutagenesis, supporting both gene discovery and trait improvement. Its versatility extends beyond model systems to major crops and wild relatives, thereby expanding opportunities for plant breeding and conservation. Recent advances, including base and prime editing, have further broadened its scope, enabling high-resolution dissection of regulatory networks and genetic pathways. By integrating genome editing into plant research, CRISPR/Cas9 offers powerful avenues for developing climate-resilient and high-yielding crops, contributing to global food security and sustainable agriculture.