Frontiers in Plant Science最新文献

The mechanisms by which low light modulates source-sink dynamics, affecting starch synthesis and formation of underground storage organs in geophyte, remain unclear. In this study, a two-year field experiment was conducted under natural light (NL) and low light (LL, 50% of NL intensity) conditions. LL resulted in a 23.66% and 21.23% reduction in corm yield in 2023 and 2024, respectively. Saffron plants under LL had larger, longer leaves with a higher proportion of dry weight (DW) compared to those under NL. Despite the marked inhibition of photosynthetic capacity, initial DW, sucrose and glucose concentrations in leaves were comparable to those under NL. Carbohydrate analysis revealed that starch concentration in the mother corms under LL decreased by 18.00% relative to NL, while sucrose and glucose concentrations increased by 28.44% and 68.44%, respectively. At the corm expansion stage, sucrose concentration in leaves and daughter corms under LL conditions was 17.32% and 54.08% higher than under NL, but glucose and starch concentrations in daughter corms were 22.08% and 10.22% lower, respectively. Additionally, the activity of invertase (INV), sucrose synthase in the decomposition direction (SUS) and ADP-glucose pyrophosphorylase (AGPase) in daughter corms were reduced under LL. LL also affected phytohormones concentrations, with increased levels of indole-3-acetic acid (IAA) and gibberellin (GA₁) in LL leaves and daughter corms, and decreased abscisic acid (ABA) levels. Transcriptome and quantitative PCR analyses showed that LL upregulated the expression of genes involved in glycolysis and the tricarboxylic acid cycle in leaves, while downregulating CsSUS, CsINV1, CsAGPS1, CsZEP, and CsNCED, which are key to sucrose hydrolysis, starch synthesis, and ABA biosynthesis. Exogenous GA₃ application further inhibited SUS, INV and AGPase activities in daughter corms, indicating that high GA concentrations impair carbohydrate metabolism in these organs. In conclusion, LL decreases saffron corm yield by promoting the allocation of reserves from mother corms to leaves at the seedling stage. By the period of the daughter corms enlargement, elevated GA₁ and IAA levels and reduced ABA concentration promote leaf growth while inhibiting carbohydrate metabolism in daughter corms, thereby reducing sucrose transport from leaves to daughter corms and suppressing corm yield formation.

Background: Bitter gourd requires well-drained sandy to sandy loam soils for optimum growth, development, and germination, while its growth is retarded in extreme saline conditions. It is very sensitive to salinity stress, which imposes devastating limits on its productivity. Thus, the impact of soil salinization on the economics of bitter gourd yield deserves scientific inquiry.

Methods: The present study was designed to evaluate the various morphological attributes (mean germination time, germination index, final emergence percentage, measurements of root length, measurement of shoot length, measurement of plant dry biomass, and measurement of plant fresh biomass), physiological attributes (leaf chlorophyll content and electrolyte leakage), biochemical attributes (proline contents, antioxidant enzymes, superoxide dismutase, catalase Q9 , and peroxidase), leaf water relations (leaf osmotic potential, leaf water potential, leaf turgor potential, and leaf relative water content), and ion concentrations (Na+, K+, Ca +, and Cl-) that can be used for the evaluation of salt stress tolerance potential in bitter gourd. The research was conducted in the field area of the Faculty of Agricultural Sciences, University of the Punjab, Lahore.

Results: In this experiment, bitter gourd seeds were sowed either without treatment or with hydropriming, 0.01%, 0.02%, 0.03%, 0.04%, and 0.05% chitosan, respectively, under 50mM soil salinity under the climatic conditions of Lahore. This research was designed to find the role of chitosan in inducing salt stress tolerance in bitter gourd plants and also find the best chitosan dose that is useful for higher salinity conditions. Different attributes of bitter gourd were recorded. Results revealed that chitosan application at 0.04% is best for enhancing the salt stress tolerance potential of bitter gourd. Different morphological attributes, physiological attributes, water relation attributes, and biochemical parameters were also recorded. It was observed that pre-sowing treatments with an optimized dose of 0.04% chitosan exhibited significant effects on all the bitter gourd plants and improved the germination rate by improving the salt stress tolerance potential of plants under high salinity.

Conclusion: It can be concluded from the present research that the optimized dose of 0.04% chitosan has also proved effective in the enzymatic activity of bitter gourd by enhancing the salt stress potential under increasing salt stress.

The olive tree (Olea europaea L.), which characterizes the agriculture of the Mediterranean basin, faces challenges adapting to high-density orchards and mechanized cultivation. This study addresses a key issue: controlling tree size to enhance efficiency and manageability in olive cultivation. Utilizing genetic mapping methods, we have identified significant Quantitative Trait Loci (QTL) and candidate genes associated with low-vigor traits in olive trees. Our research on the 'Koroneiki' F2 progeny, which exhibits low vigor traits but remains underutilized in breeding programs, has pinpointed a QTL linked to trunk basal diameter-a trait correlated with plant height based on morphological measurements. Results underscore a strong genetic control of these traits, with a consistent correlation observed over time. We identified two candidate genes - Acid Phosphatase 1, Shikimate O-hydroxycinnamoyltransferase, and a SNP Marker likely associated with Calcium Responsive Proteins - each potentially interacting with plant hormones to influence growth. Controlling olive tree size presents several challenges, including the genetic complexity of polygenic traits like size and vigor, and limited rootstock options. By integrating reference genomes with our genetic analysis, we offer a conceptual advancement that could substantially accelerate breeding timelines compared to traditional approaches. Although genome editing is still a future possibility due to the complexity of olive genetics and the species' recalcitrance to transformation, our study lays a foundational understanding to guide future breeding programs. By targeting the identified candidate genes, this research represents a pivotal step toward selecting new low-vigor genotypes and rootstocks, contributing to innovations in olive cultivation.

Introduction: Blumea balsamifera, a half-woody plant belonging to the Asteraceae family, is valued as both a medicinal and industrial crop primarily for its phytochemical component, (-)-borneol. Nitrogen (N) is essential for regulating the growth of B. balsamifera and the biosynthesis of (-)-borneol; however, the molecular mechanisms by which N influences these processes remain inadequately understood. This study aimed to elucidate the effects of N on growth and (-)-borneol synthesis at the molecular level.

Methods: A field experiment was conducted in which B. balsamifera plants were fertilized with three different nitrogen regimes: 0 kg N ha^-1 (control, CK), 150 kg N ha^-1 (N1 treatment), and 300 kg N ha^-1 (N2 treatment). Physiological and biochemical assessments were performed to evaluate the growth and metabolic responses of the plants under these varying N conditions. Additionally, transcriptome sequencing of leaves of B. balsamifera was conducted to elucidate the underlying molecular mechanisms involved.

Results and discussion: The results indicated that both the N1 and N2 treatments significantly promoted the growth of B. balsamifera, with the 150 kg N ha^-1 treatment (N1) resulting in the most favorable effects. Under the N1 treatment, the leaves harvested in October, November, and December exhibited the highest accumulation of (-)-borneol, with yields of 782 mg plant^-1, 1102 mg plant^-1, and 1774 mg plant^-1, respectively, which were significantly different from those observed in the CK and N2 treatments. Comparative transcriptome analysis revealed a total of 6,714 differentially expressed genes (DEGs). Notably, several DEGs associated with auxin signaling and N metabolism were upregulated in the N1 and N2 treatments. In contrast, many DEGs related to carbohydrate metabolism, terpenoid backbone biosynthesis, monoterpenoid biosynthesis, and flavonoid biosynthesis were significantly upregulated in the CK treatment. Moreover, potential transcription factors (TFs) that may link N nutrition with the synthesis of medicinal components were identified. Our study demonstrates that N can enhance the accumulation of (-)-borneol in B. balsamifera when applied in appropriate quantities. These findings provide a comprehensive understanding of the relationship between N nutrition and (-)-borneol yield in B. balsamifera, offering valuable insights for future cultivation practices.

Sesamum indicum, a highly esteemed oil crop, has exhibited remarkable value and potential in diverse areas encompassing the economy, food industry, and health. We have observed that there are small protrusions on the leaves of the indehiscent capsule material G1358. No obvious difference was detected on overall auxin content between the leaves of G1358 and LZ1 from metabolomic analysis. However, auxin levels at the base of G1358 leaves were notably higher than in LZ1, suggesting a correlation between the small protrusions at the base and polar auxin transport (PAT). PAT is essential for regulating growth and development across different plant tissues. PAT primarily relies on three families of transporter proteins: ABCB, PIN, and AUX/LAX. However, the ABCB, PIN, and AUX/LAX protein families in Sesamum indicum have not been systematically characterized. Herein, we identified 21 SiABCBs, 11 SiPINs, and 5 SiLAXs in S. indicum. Our analysis indicated that tandem duplications have facilitated the expansion of SiLAX, SiPIN, and SiABCB gene families, which have undergone purifying selection throughout their evolutionary history. Transcriptome screening and RT-qPCR analysis revealed that SiABCB3, SiABCB6, and SiPIN10 positively regulate PAT, whereas SiABCB7 and SiABCB9 negatively regulate PAT in G1358. These regulatory interactions contribute to the formation of small protrusions in G1358 leaves and enhance the rate of photosynthesis. Our findings provide a theoretical foundation for understanding PAT genes and their roles in the environmental adaptation of sesame.

Poor nutrient use efficiency (NUE) and water use efficiency (WUE) is a predominantly faced problem in semi-arid regions that limit the crop production. This problem can be addressed with the application of zeolite that is a naturally available mineral with very high cation exchange and water holding capacity, which aids in improving NUE and WUE. Moreover, zeolites are safe for the environment and living organisms, and their use in agriculture results in improving physical and chemical properties of soil. Yet, its study is very limited in semi-arid regions of India. Thus, a study was conducted with locally available zeolite at CRIDA, Hyderabad. Zeolite was further characterized using X-ray diffraction (XRD) and SEM, as the type of zeolite collected is unknown from local market. The results of XRD and SEM revealed that the zeolite collected was mordenite zeolite. Our study includes laboratory and pot experiment where laboratory includes sorption and leaching column study to evaluate the zeolite capacity to hold and release the nutrients especially NH₄ ⁺, P, and K. In this study, the adsorption behaviour of the natural mordenite was examined, and it was found that the maximum adsorption capacity for NH₄ ⁺, P, and K were estimated as 10.6, 1.08, and 2.15 mg g^-1, respectively, suggesting the zeolite has good affinity for N. Furthermore, the column study revealed that there was 15.4% reduction in NH₄ ⁺-N loss with 10 tonnes zeolite ha^-1 + N @ 100 kg ha^-1 as compared to N alone, while the reduction was 39.6% with 10 tonnes zeolite ha^-1 + N @ 500 kg ha^-1 compared to N alone, suggesting that the zeolite could control the release of N as compared to the sole application of N, which was supplied through urea. In addition, pot experiment was carried out with three levels of fertiliser rates, four levels of zeolite, and two levels of moisture in randomised complete block design with three replications to evaluate the changes in soil available nutrients and their uptake in tomato. Results revealed that there was a significant positive impact on yield, water use efficiency, nutrient (N, P, and K) uptake, and soil available nutrients. Highest soil available N, P, and K, crop uptake, and yield were observed due to zeolite application @ 200 kg ha^-1 along with 100% recommended dose of fertilization in Alfisols. Thus, zeolite application along with chemical fertilisers can improve the nutrient availability by reducing the leaching losses and improving nutrient use efficiency.

Phenotypic traits like plant height are crucial in assessing plant growth and physiological performance. Manual plant height measurement is labor and time-intensive, low throughput, and error-prone. Hence, aerial phenotyping using aerial imagery-based sensors combined with image processing technique is quickly emerging as a more effective alternative to estimate plant height and other morphophysiological parameters. Studies have demonstrated the effectiveness of both RGB and LiDAR images in estimating plant height in several crops. However, there is limited information on their comparison, especially in soybean (Glycine max [L.] Merr.). As a result, there is not enough information to decide on the appropriate sensor for plant height estimation in soybean. Hence, the study was conducted to identify the most effective sensor for high throughput aerial phenotyping to estimate plant height in soybean. Aerial images were collected in a field experiment at multiple time points during soybean growing season using an Unmanned Aerial Vehicle (UAV or drone) equipped with RGB and LiDAR sensors. Our method established the relationship between manually measured plant height and the height obtained from aerial platforms. We found that the LiDAR sensor had a better performance (R² = 0.83) than the RGB camera (R² = 0.53) when compared with ground reference height during pod growth and seed filling stages. However, RGB showed more reliability in estimating plant height at physiological maturity when the LiDAR could not capture an accurate plant height measurement. The results from this study contribute to identifying ideal aerial phenotyping sensors to estimate plant height in soybean during different growth stages.

To explore the flavor related regulatory mechanisms of fresh Corylus heterophylla × Corylus avellana, a joint analysis of metabolome and transcriptome were utilized to compare the two typical C. heterophylla × C. avellana varieties with different flavors ('yuzhui' and 'pingou21') in this paper. The results showed that the genes including E2.4.1.67-1, E2.4.1.67-2, SUS-1, SUS-2, SUS-4, SUS-5, SUS-7, SUS-8, SUS-9, UGP2-2 were identified as responsible for regulating the levels of stachyose, manninotriose and raffinose in hazelnuts. CS and OGDH were deemed as the genes involved in the citric acid cycle, which was a central metabolic pathway that generated energy through the oxidation of carbohydrates, fats and proteins in hazelnuts. The genes trpD, ALDO, PK-1, PK-2, ilvH, argE-1, argE-4, argE-5, argD, PDAH, GLTI were regarded as involved in the biosynthesis of various amino acids like tryptophan, valine, alanine, and arginine. These amino acids determined the taste of C. heterophylla × C. avellana and were important precursors of other flavor-related compounds. The genes LOX2S-2, LOX2S-3, LOX2S-4 and LCAT3 were viewed as involved in the regulation of lipid biosynthesis, specifically involving 13(S)-HPODE, 9,10,13-trihome and 13(S)-HOTrE in C. heterophylla × C. avellana. These findings highlight the significance of genes and metabolites and internal regulatory mechanisms in shaping the flavor of fresh C. heterophylla × C. avellana cultivated in temperate continents. This study provides the theoretical basis for breeding excellent food functional hazelnut varieties.

Benzylisoquinoline alkaloids (BIAs) are a prominent class of plant metabolites with significant pharmaceutical and industrial significance that have garnered substantial attention from researchers worldwide. BIAs exhibit several pharmacological activities and have been used extensively. Examples include analgesics such as morphine, tetrahydropalmatine, antimicrobials such as berberine, and antineoplastic agents including cepharanthine. Most BIAs are derived and isolated from medicinal plants; however, these plants are predominantly wild resources that are scarce. Their high environmental impact, slow growth rate, scarcity of resources, and expensive direct extraction costs pose a significant challenge. Certain BIAs are present in trace amounts in medicinal plants; moreover, they have complex chemical structures and unstable properties. Designing chemical synthesis routes and processes is challenging. Thus, a major obstacle in developing and utilizing these natural products in the pharmaceutical industry lies in their low abundance in nature. Consequently, the limited supply of these molecules fails to meet high research and market demands. In recent years, biosynthesis approaches have emerged as a novel and efficient method to obtain BIAs. In this review, recent progress in the field of enzymes related to the elucidation of biosynthetic pathways and the biosynthesis of BIAs are discussed, and future perspectives for designing viable strategies for their targeted manipulation are presented.

Introduction: Soil chemical properties and bacterial communities play key roles in shaping tea plant nutrient status and quality. While the relationships between soil bacterial communities and plant nutrient status have been investigated, the specific role by which soil bacterial communities interacted with soil properties to influence tea plant nutrients and quality remained underexplored.

Methods: In this study, different soil types were collected from tea gardens and designated as soil A (pH 3.41), soil B (pH 3.75), soil C (pH 4.16), soil D (pH 4.17) and soil E (pH 5.56) based on the initial soil pH. We conducted pot cultivation of tea plant 'Yabukita' to investigate how soil chemical factors affect bacterial communities and their influences on the nutrient status and quality of tea plants, and finally explored the complex relationships between soil bacterial features and tea quality.

Results and discussion: The results showed that soil bacterial α-diversity was higher level in soils D and E, with distinct β-diversity patterns separating higher pH soils (D and E) from lower pH soils (A, B, and C). The dominant amplicon sequence variants (ASVs) in soils were Proteobacteria (28.12%), Actinobacteriota (25.65%), Firmicutes (9.99%) at phylum level, and Acidothermaceae (7.24%), Solirubrobacteraceae (4.85%), and Acetobacteraceae (4.50%) at family level. Soil pH, exchangeable Mg²⁺, and Ca²⁺ were identified as key factors shaping bacterial community composition and positively correlated with bacterial diversity. Differentially abundant ASVs (DAAs) among all soils were also identified including the phylum Firmicutes and families such as Paenibacillaceae, Alicyclobacillaceae, JG36-TzT-191, KF-JG30-C25, and Acidobacteriaceae_subgroup1. Besides, the nutrient content of tea new leaves varied significantly among soil types and harvests. Combined with Mantel-test association analysis, soil chemical properties and soil bacterial communities were jointly correlated with the contents of total nitrogen, potassium, calcium, aluminum, magnesium, free amino acids, and caffeine in tea new leaves. These findings highlight the dynamic interactions between soil properties, bacterial communities, and tea nutrients, emphasizing the importance of optimizing soil health and bacterial networks to improve tea quality.