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Xanthomonas oryzae pv. oryzae (Xoo) is a widespread pathogen causing bacterial leaf blight (BLB) disease, devastating rice productivity in many cultivated areas of Thailand. A specific and simple method for Xoo detection is required to improve surveillance of disease transmission and outbreak. This study developed a recombinase polymerase amplification (RPA) assay assisted with CRISPR-cas12a assay (RAC) for Xoo detection from bacterial cell suspension of infected rice samples without DNA extraction. The efficiency of the RAC system for Xoo detection using either Xoo80 or Xoo4009 locus was optimized to amplify and determine the sensitivity and specificity using a Xoo DNA template from bacterial cell suspension of infected rice samples without DNA extraction. The RAC system using the Xoo4009 locus gave a higher specificity than Xoo80 locus, because only Xoo species was amplified positive RPA product with fluorescence signal by cas12a digestion, which indicated no cross reactivity. Optimal RAC using the Xoo4009 locus enabled diagnosis of Xoo presence from both plant extracted samples of Xoo artificially inoculated rice leaves within 3 d post-inoculation without symptomatic BLB appearance, and Xoo naturally infected rice. Findings exhibited that RAC using the Xoo4009 locus offered sensitivity, specificity and simplicity for Xoo detection, with low intensities of Xoo -DNA (1 × 103 copies/μL) and Xoo -cell (2.5 × 103 cfu/mL). This developed RAC system showed significantly potential for Xoo detection at point-of-care application for early signs of BLB disease outbreak in rice fields. [ABSTRACT FROM AUTHOR]

Bacterial leaf blight (BLB) and bacterial leaf streak (BLS) are highly destructive diseases that severely impact rice production when outbreaks occur, especially BLB. Timely identification of Xanthomonas oryzae pv. oryzae (Xoo) and Xanthomonas oryzae pv. oryzicola (Xoc) as the causative agents of these diseases is crucial to prevent and manage their spread. This study developed a detection method called loop-mediated isothermal amplification with lateral flow dipstick (LAMP-LFD) to facilitate the surveillance of Xoo and Xoc in rice fields. LAMP-LFD using either Xoo80 or Xoc3863 to detect Xoo and Xoc , respectively was subjected to a heat block at 63 °C for 50 min. The LAMP products from both reactions were then hybridized with Xoo or Xoc specific probes in a single reaction and examined using a lateral pad with two tested lines. LAMP-LFD using Xoo80 or Xoc3863 demonstrated high specificity, yielding no false positives for other bacterial species. The sensitivity of LAMP-LFD using Xoo80 (with a detection limit of 2.5 × 104 cfu/ml) was ten-fold higher than Xoc3863 (with a detection limit of 2.5 × 105 cfu/ml). To evaluate the efficacy of this approach, 42 rice field samples were tested, resulting in the detection of nine and seven positives for Xoo and Xoc , respectively with two samples indicating the presence of both. LAMP-LFD using either Xoo80 or Xoc3863 showed significant promise as a simultaneous detection tool for Xoo and Xoc surveillance and management of rice disease outbreaks, ultimately reducing rice yield losses. [Display omitted] • LAMP-LFD exhibits specific detection for Xoo and Xoc in <90 mins. • LAMP-LFD enables dual detection of Xoo and Xoc in a single strip. • The limit of detection is as low as 0.2 ng/μl of gDNA and 2.5 × 105 cfu/ml of bacterial cell. • LAMP-LFD can be used for Xoo and Xoc detection in rice leaves samples. [ABSTRACT FROM AUTHOR]

Xanthomonas oryzae pv. oryzae (Xoo) is a major pathogen of rice, leading to tremendous rice yield reduction about 20–50% both temperate and tropical rice-growing regions. Here, to develop a rapid and reliable method for Xoo detection, a one-step colorimetric loop-mediated isothermal amplification (cLAMP) assay was established. The conditions for cLAMP using both LpXoo80 and LpXoo4009 primer sets were optimized. The specificity and sensitivity of cLAMP using both primers were determined under the optimal conditions of 60 °C for 40 min that the results can be visualized by naked eye. As a result, cLAMP using LpXoo4009 primer amplifying in only Xoo exhibited higher specificity than LpXoo80 primer, generating a cross-reaction of LAMP amplification in both Xoo and other Xanthomonas species (Xag and Xac). cLAMP using LpXoo80 primer showed higher sensitivity than the LpXoo4009 primer, with consistently amplified positive cLAMP products under detected thresholds of at least 2 × 103 and 2 × 105 cfu/mL, respectively. This developed cLAMP assay was applied to detect Xoo artificially inoculated rice leaf (2.5 × 108 cfu/mL). Positive LAMP product was clearly detected over the first 2 days post-inoculation, while external BLB leaf symptoms disappeared. This cLAMP assay also showed high performance of Xoo detection (>80%) in Xoo naturally infected rice leaf samples, harvested from suspected BLB symptomatic leaf in cultivated rice fields. The work reported a high specificity, sensitivity, and simplicity of the cLAMP assay to detect various Xoo isolates identified from the lower north region of Thailand. This method provided feasible point-of-care testing for Xoo surveillance in fields and long-term BLB disease management. [Display omitted] • One-step colorimetric LAMP assay (cLAMP) enables detection of Xoo with naked eye. • cLAMP using LpXoo4009 offers the Xoo specificity and high sensitivity. • cLAMP displays a rapid method to be completed in 2 h. • cLAMP accelerates the point-of-care testing for Xoo surveillance and control in rice field. [ABSTRACT FROM AUTHOR]

Brahmi ( Bacopa monnieri (L.) Wettst.) is extensively used as a nutritional supplement in various commercial products as the plant contains abundant phytochemicals and has antioxidant properties. This study assessed the phytochemical contents, antioxidant properties, and DNA damage protection among seven Brahmi products sold through Thai online markets. Results showed that the P6 sample exhibited 3.5-7.5 fold higher bacoside contents than values observed in the other six product samples. The P6 sample also demonstrated the highest TTC, TFC, and TPC compared to the other brands. For antioxidant activity, the samples (P1-P7) displayed high capacity to scavenge DPPH free radicals with slightly significant differences ranging from 78.37 ± 0.25 to 87.21 ± 0.05 at p -value ≤0.01. The P6 sample showed strong protection against H 2 O 2 -induced oxidation of DNA strand breakage, indicating highly potent phytochemical compounds with effective free radical scavenging activity, and the ability to prevent DNA damage. The P6 sample showed promise as a valuable ingredient for the development of functional food products. However, further in vivo animal and clinical studies are required to explore the neuroprotective enhancement effects of Brahmi extracts., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

Centella asiatica (L.) Urb. has wound healing, anti-inflammatory, cognitive improvement, and neuroprotective properties which have been attributed to its centelloside content. However, the quantities of these bioactive compounds are limited and vary due to genetic and environmental factors. Light qualities are known to enhance the production of secondary metabolites in several plant species, both preharvest and postharvest. In this study, fresh leaves of C. asiatica were subjected to different light emitting diode (LED) quality including white, dark, red, blue, and green to assess centelloside content, phytochemical constituents, and transcription level expression of triterpenoid biosynthesis genes. Results showed that white and blue LEDs significantly increased centelloside content in C. asiatica leaves at 3 days postharvest (dph) by 73 % over the control group at 0 dph. Blue LEDs stimulated the expression of triterpenoid biosynthesis genes including C. asiatica squalene synthase ( CaSQS ), C. asiatica β-amyrin synthase ( CabAS ), and C. asiatica UDP gluclosyltransferase-73AH1 ( CaUGT73AH1 ; CaUGT ), while different LED conditions gave diverse results. Red LED treatment triggered higher total flavonoid content (TFC) and total triterpenoid content (TTC) while white LEDs enhanced total triterpenoid content (TTC). Taken together, our findings suggest that postharvest under blue LEDs is a great approach to increase centelloside production of C. asiatica through gene up-regulation in triterpenoid pathway. Therefore, postharvest technology by LEDs serves as an effective tool for improving raw material quality for medicinal plant industries., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors. Published by Elsevier Ltd.)

Banana ( Musa spp.) is a major global economic fruit crop. However, cross-pollination from other Musa cultivars grown in nearby plantations results in seeded fruit that exceeds market demand. This study investigated pollen viability and germination and examined the expression profiles of pollen development-related genes across seven Musa genomes (AA, BB, AAA, BBB, AAB, ABB and ABBB). Twenty-three Musa cultivars were assessed for pollen viability using lacto-aceto-orcein and triphenyltetrazolium chloride staining methods. Results revealed that pollen viability obtained from both methods was significantly different among all the studied cultivars. Cultivars carrying BB (diploid) genomes had higher viability percentages than AA (diploid), AAA, BBB, AAB and ABB (triploid) and ABBB (tetraploid) genomes. Germination of the studied cultivars was also investigated on pollen culture medium, with results showing significant differences between the pollen of each cultivar. The best germinating cultivar was TKM (11.0 %), carrying BB genome. Expression profiles of pollen development-related genes by RT-qPCR indicated that both TPD1A and MYB80 genes were highly expressed in triploid Musa genomes but the PTC1 gene showed down-regulated expression, resulting in non-viable pollen. Pollen viability, pollen germination and pollen development-related genes differed across Musa cultivars. This knowledge will be useful for the selection of male parents for Musa cross-breeding programs. Pollen viability should also be considered when planning Musa production to avoid seeded fruit., Competing Interests: The authors declare there are no conflicts of interests., (© The Author(s) 2023. Published by Oxford University Press on behalf of the Annals of Botany Company.)

Bacopa monnieri is a medicinal herb that is increasing in demand in Thailand. However, the lack of high-bacoside cultivars has limited pharmaceutical utilization and production. Here, chromosome doubling in B. monnieri was attempt to improve biomass and bacoside content in its seedling. Nodal segments were treated with colchicine (0, 0.025, 0.05, 0.075, 0.1, and 0.5% w/v) for 24 or 48 h before transferring to multiple shoot induction medium (1/2 MS medium supplemented with 0.2 mg L -1 BAP). Of 326 tested clones, 18 and 84 were mixoploids and autotetraploids, respectively. The highest autotetraploid-induction percentage (14.6%) was found after treated with 0.5% (w/v) colchicine, and 48 hours exposure. From 28 selected autotetraploid clones, 21 and 13 have significantly higher fresh and dry weight compared to the diploid clone, respectively. The maximum fresh and dry weight of autotetraploid plants was 2.8 and 2.0-time higher than diploid plants, respectively. Moreover, the maximum total bacoside content (1.55 mg plant -1 ) was obtained from an autotetraploid plant, which was 2.3-fold higher than the level in diploid plants. These novel autotetraploids have the potential to be developed as resources for value-added improvements in the medicinal and pharmaceutical industries., Competing Interests: The authors declare there are no competing interests., (©2019 Inthima and Sujipuli.)

Epipactis flava Seidenf. is an endangered Thai rheophytic orchid that has recently shown a rapid decrease in its natural habitat, prompting an urgent need for conservation using ex situ reintroduction methods. Temporary immersion system (TIS) has been successfully applied for large-scale propagation in various plants species. Propagation efficiency of E. flava using TIS was investigated and compared with conventional semi-solid system (SSS) and liquid continuous immersion system (CIS). The highest percentage of new shoot and shoot bud formation was obtained from TIS, followed by CIS and SSS, respectively. Growth parameters as indicated by number of new shoots, shoot buds, shoot height and leaves per explant were significantly higher using TIS than with SSS and CIS. Moreover, the maximum number of new shoots and shoot buds per replication were reliably obtained from TIS higher than SSS and CIS. After acclimatization, the highest survival percentage of plantlets was observed in TIS (76.7%), with 60% surviving after eight weeks of transplantation in artificial stream. TIS was determined as the most suitable culture system for in vitro mass propagation of E. flava compared to CIS and SSS.

Gibberellins (GAs) are the plant hormones that control many aspects of plant growth and development, including stem elongation. Genes encoding enzymes related to the GA biosynthetic and metabolic pathway have been isolated and characterized in many plant species. Gibberellin 2-oxidase (GA2ox) catalyzes bioactive GAs or their immediate precursors to inactive forms; therefore, playing a direct role in determining the levels of bioactive GAs. In the present study, we produced transgenic plants of the liliaceous monocotyledon Tricyrtis sp. overexpressing the GA2ox gene from the linderniaceous dicotyledon Torenia fournieri (TfGA2ox2). All six transgenic plants exhibited dwarf phenotypes, and they could be classified into two classes according to the degree of dwarfism: three plants were moderately dwarf and three were severely dwarf. All of the transgenic plants had small or no flowers, and smaller, rounder and darker green leaves. Quantitative real-time reverse transcription-polymerase chain reaction (PCR) analysis showed that the TfGA2ox2 expression level generally correlated with the degree of dwarfism. The endogenous levels of bioactive GAs, GA1 and GA4, largely decreased in transgenic plants as shown by liquid chromatography-mass spectrometry (LC-MS) analysis, and the level also correlated with the degree of dwarfism. Exogenous treatment of transgenic plants with gibberellic acid (GA3) resulted in an increased shoot length, indicating that the GA signaling pathway might normally function in transgenic plants. Thus, morphological changes in transgenic plants may result from a decrease in the endogenous levels of bioactive GAs. Finally, a possibility of molecular breeding for plant form alteration in liliaceous ornamental plants by genetically engineering the GA metabolic pathway is discussed., (Copyright © 2013 Elsevier GmbH. All rights reserved.)