Acta Physiologiae Plantarum最新文献

This study investigated the influence of specific light-emitting diodes (LEDs) on lettuce seed germination, growth, and the accumulation of health-promoting compounds. The results revealed that LED lights significantly impacted both red (Jeok Chi Ma) and green (Cheong Chi Ma) lettuce cultivars and compared to natural light. Red (R)-blue (B) light combinations accelerated germination in the red cultivar, while R light alone had the opposite effect in the green cultivar. R light enhanced shoot fresh weight for both cultivars, with the combination of R-B light showing promising results as well. B light promoted root growth in both cultivars, followed by white light. R light maximized root length (RL), while blue and white light were most effective for root volume (RV). B light significantly increased the levels of health-promoting compounds like phenolics (PCs), anthocyanins (ANTs), and chlorophyll a (Chl a) and chlorophyll b (Chl b) in both cultivars. Red light, on the other hand, maximized carotenoids (CARs) content. Natural light resulted in the lowest levels of these compounds. Blue and R light respectively stimulated the expression of key genes in the ANTs and CARs biosynthetic pathways, with varying responses observed between the red and green cultivars. Overall, this study highlights the potential of utilizing specific LED light wavelengths to optimize lettuce growth and enhance the accumulation of health-promoting compounds. The findings suggest that tailoring light spectrums based on cultivar type can be a valuable strategy for controlled environment agriculture.

DEAD-box RNA Helicases (RHs) have been proved effective in plants against stress conditions, increasing their tolerance to different environmental stresses. To date, many different studies have revealed the occurrence of these proteins in many plants; however, studies of DEAD-box RHs in wheat, particularly those targetted to chloroplast, are still waiting to be studied. In this article, we performed an extensive genome-wide analysis of DEAD-box RHs in wheat genome. The results revealed that wheat genome consists of 116 RHs that have been retrieved using https://plants.ensembl.org/index.html. Among the 116 DEAD-box RHs, 50 were found to have the DEAD motif. While 39, out of 50 were found predicted to be localized to chloroplast by analyzing amino acid sequence of the DEAD-box RHs using a web-based prediction server (http://avermitilis.ls.kitasato-u.ac.jp/chlorop/). These 39 DEAD-box RHs were found to have sequences of chloroplast transit peptide (cTP). The predicted chloroplast localized DEAD-box RHs were analyzed for their distribution on chromosome and found unevenly distributed across the 21 chromosomes of common bread wheat. DEAD-box RHs with more than 40 cTP length were selected and proceeded for the analysis of expression patterns under drought, heat, and salt stress conditions. The results revealed that TraHEN2, TraRH47a, TraRH47c, TraISE2 (6A, 6B), TraRH58, TraRH22 (5A, 5B, 5D), and TraRH39 (3A) were highly induced in heat stress, while the expressions of TraRH47 (a, and b), TraSTRS2 (3A), TraRH22 (5B, 5D) and TraRH39 (3A) were increased many folds under salt stress. Under drought stress the transcript level of TraRH47 (A, B), TraSTRS2 (3A), TraRH58, TraRH22 (5A, 5B) and TraRH39 were highly induced. However, expressions of TraRH33 remained reduced in all stresses. This study concludes that high induction of the mentioned DEAD-box RHs under drought, salt and heat play important role in wheat responses to abiotic stress conditions. The study may lead the foundation that over-expression of these genes in wheat and other crops may develop stress-resistance, which may lead to high yield and possibly meet the demands of the increasing population.

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.