Naphthalene Acetic Acid Treatments Research Articles

The combined analysis of transcriptome and phytohormone provides new insights into signaling mechanism for lateral root formation of tea plant (Camellia sinensis)

The growth and development of lateral roots (LRs) determine the nutrient absorption and environmental adaptability of tea plant, playing a crucial role in the economic efficiency of tea plantations. However, the molecular mechanisms underlying the formation of LRs in tea plant remain unreported. In this study, we established a LRs induction system in tea plants by exogenously adding N-1-naphthylphthalamic acid (NPA) and naphthaleneacetic acid (NAA). The molecular mechanisms of LRs formation were analyzed through transcriptomics and endogenous hormone measurements. Results showed that NAA treatment could counteract the inhibitory effect of NPA on LRs formation and promote the generation of LRs in tea plant. The addition of exogenous NAA reduced the levels of auxin and zeatin in the root tips while increasing the content of abscisic acid (ABA). Transcriptomic analysis at four time points (2, 6, 12, and 24 h) after NAA vs. MOCK treatment revealed 78 different expression genes (DEGs) associated with plant hormone signaling pathways. Among these, the auxin signaling pathway was the most significant in responding to the LRs formation in tea plant. Weighted Gene Co-Expression Network Analysis (WGCNA) identified the Mitogen-Activated Protein Kinases (MAPK) signaling pathway as responsive to NAA treatment, participating in the formation of LRs in tea plant. This study provides potential signaling pathways for the investigation of LRs formation in tea plant and identifies candidate genes for further research into tea plant root system architecture (RSA).

Effect of chemical thinning on fruit growth and fruit quality of ‘Majhoul’ date palm at the end of the ‘Khalal’ stage

The aim of this research work was to study the effect of chemical thinning using NAA (Naphthalene acetic acid) and the manual thinning used by the farmer on the fruit growth and fruit quality of ‘Majhoul’ date palm at the end of the ‘khalal’ stage (color stage and fruit physiologically mature). Trials were carried out on an adult plantation in the Tinejdad region, Tafilalet area. Observations focused on monitoring the fruit growth of different flowering phases and fruit quality at the end of the ‘khalal’ stage. Obtained results showed that the evolution of the fruit size parameters is similar for all flowering phases and all thinning treatments and at the end of the ‘khalal’ stage there is no significant difference (p ˃ 0.05) between flowering phases and between thinning treatments for these parameters. At the end of the ‘khalal’ stage, fruit length is between 4.8 and 4.9 cm and fruit mass is between 25.0 and 25.5 g. The content of sugar in the fruit is higher at the manual thinning treatment than at the NAA treatments, whereas the flowering phases have no effect on this parameter. The pH of the fruit juice is relatively similar for all thinning treatments and all flowering phases.

Integrated Analysis of Transcriptome and Metabolome to Unveil Impact on Enhancing Grape Aroma Quality with Synthetic Auxin: Spotlight the Mediation of ABA in Crosstalk with Auxin.

It is widely accepted that prevéraison application of naphthaleneacetic acid (NAA) can delay the ripening of grapes and improve their quality. However, how NAA impacts grape aroma compound concentrations remains unclear. This study incorporated the analyses of aroma metabolome, phytohormones, and transcriptome of Vitis vinifera L. cv. Cabernet Sauvignon grapes cultivated in continental arid/semiarid regions of western China. The analyses demonstrated that NAA application increased β-damascenone and 1,1,6-trimethyl-1,2-dihydronaphthalene (TDN) in the harvested grapes by delaying véraison and upregulating VvPSY1 and VvCCD4b expressions. Additionally, NAA treatment decreased 2-isobutyl-3-methoxypyrazine (IBMP) at the same phenological stage. Notably, abscisic acid (ABA) levels increased in NAA-treated grapes during véraison, which triggered further changes in norisoprenoid metabolisms. The ABA-responsive factor VvABF2 was potentially involved in VvPSY1 positive modulation, while the auxin response factor VvARF10 may play a role in VvCCD4b upregulation and VvOMT2 downregulation during NAA induction. VvARF10 possibly acts as a crosstalk node between the ABA and auxin signaling pathways following NAA treatment in regulating aroma biosynthesis.

In Vitro Shoot Culture Growth of Pontianak Orange (Citrus nobilis var. microcarpa) with the Addition of Naphthalene Acetic Acid and 6-Benzyl Amino Purine

Pontianak siam orange (Citrus nobilis var. microcarpa) is an important agricultural commodity unique to Sambas Regency, West Kalimantan. The demand for Pontianak siam oranges has been steadily increasing over the years, yet the production of Pontianak oranges has not been able to meet the domestic demand. The limited availability of superior seedlings is one of the reasons for this situation. Therefore, efforts are needed to fulfill the demand for Pontianak siam oranges by producing a large quantity of superior seedlings in a short period. One of the strategies that can be employed is in vitro propagation. This research aims to observe the growth of Pontianak Siamese orange shoot explants after administration of NAA (Naphthalene Acetic Acid) and BAP (6-Benzyl Amino Purine). This research was conducted from January to June 2023 at the Tissue Culture Laboratory of the Department of Biology, Faculty of Mathematics and Natural Sciences, Tanjungpura University. The study employed a Completely Randomized Design (CRD) with two treatment factors namely NAA concentrations with 4 levels (0; 0.25; 0.5; 0.75 mg/L), and BAP concentrations with 5 levels (0; 0.5; 1; 1.5; 2 mg/L). Parameters observed were the emergence time of shoot, shoot number, height of shoot, and the number of leaves. The results showed that single NAA, single BAP, and combination treatment of NAA and BAP significantly affected all growth parameters. Treatment with the addition of 0.25 mg/L NAA and 1 mg/L BAP (A1B2) was the treatment with the fastest shoot emergence time (2.80 days after planting), the largest number of shoots (2.60 shoots)the tallest shoots (1.50 cm), , and the greatest number of leaves (2.60 leaves).

Effect of chemical thinning on the fruit parameters of ‘Majhoul’ date palm during fruit development

The aim of this work was to study the effect of NAA (Naphthalene acetic acid) on the chemical thinning of ‘Majhoul’ date palm in order to use this operation as an alternative to manual thinning, which is a costly operation carried out by the farmers. Experiments were carried out on an adult plantation of ‘Majhoul’ cv in Tafilalet area. Thinning treatments used were T0 (control treated with water), T1 (application of 150 and 300 ppm NAA 30 and 60 days after pollination), T2 (application of 250 and 500 ppm NAA 30 and 60 days after pollination) and T3 (manual thinning performed by the farmer). These treatments were used on three flowering phases of this variety. Obtained results showed that for the early flowering phase, T2 NAA treatment increased fruit drop for 77% compared to the control. Thinning treatments T1, T2 and T3 yielded fruit with larger size (fruit mass of 17.26, 18.51 and 20.88 g respectively) than that of the control (13.67 g). The late flowering phase also gave fruit with larger size (fruit mass of 18.73 g and fruit length of 4.44 cm) than that of the other flowering phases (fruit mass of 17 g and fruit length of 4.34 cm for the other flowering phases).

Fruit set in Majhoul date palm and fruit drop by chemical thinning

Date palm is very cultivated in Draa-Tafilalet area (the southeastern part of Morocco). The variety diversity is rich and include commercial varieties such as ‘Majhoul’ and ‘Bouffegous’. Fruit thinning consists of reducing the fruit load of date palm in order to obtain a balance between yield and fruit quality and to avoid alternating production. Naphthalene acetic acid (NAA) spray is used on date palm to induce fruit drop. Chemical thinning with NAA has been the subject of several research studies, which have focused on the effectiveness of the operation, the doses used and the periods of its application. The practice is not yet well mastered in Morocco and its advantages are not well known. Our work aims to study the fruit set and the effect of NAA treatments on fruit drop of ‘Majhoul’ date palm . Trials were carried out on an adult plantation in Tafilalet area and obtained results showed that fruit set in the early flowering phase was higher (more than 57%) than in the seasonal (55%) and late (42%) phases. Fruit drop is low before the application of NAA (2.41 fruits/spikelet for the seasonal flowering), while it is higher after its application (7.53 fruits/spikelet for the same phase). This is due to the best period chosen for the first application of NAA (100 ppm) and which favored fruit drop during the first stage of fruit development. The second application of NAA (200 ppm), even with a double dose than the first application, did not significantly affect fruit drop because the fruits are in an advanced stage of their development.

Enhancing Chilli Cultivation in Rain-Fed Regions: The Role of Naphthalene Acetic Acid and Gibberellic Acid

Chilli cultivation in rain-fed regions faced challenges due to environmental factors that resulting in reduced yields. To address these challenges and optimize chilli cultivation in such moisture stress conditions, a study was conducted to investigate the effects of Naphthalene Acetic Acid (NAA) and Gibberellic Acid (GA3) as foliar sprays on the growth and yield parameters of chilli plants in 2022 at Ramghat, Surkhet, Nepal. The study utilized a Randomized Completely Block Design (RCBD) with different concentrations of NAA and GA3 as treatments, along with a control group. Various growth parameters such as plant height, number of branches and leaves per plant were monitored, along with yield parameters including fruit stalk length, fruit diameter, and yield per plant. The results indicated that NAA at 50 ppm significantly increased plant height, number of branches and leaves per plant compared to the control group at all growing stages. GA3 at different concentrations also generally resulted in higher phenotypic plant characters compared to the control and NAA treatments. However, high concentrations of both NAA and GA3 had negative effects on plant growth. In terms of yield parameters, both NAA and GA3 treatments showed promising results, with increased yield per plant compared to the control group. Notably, GA3 at 50 ppm demonstrated the highest yield per plant. These findings suggest that NAA at 50 ppm and GA3 at 50 ppm had the potential to enhance chilli cultivation in rain-fed regions by improving growth and increasing yields. The study provides valuable insights for chilli farmers especially to mitigate the challenges posed by moisture stress and improve profitability particularly in rain-fed conditions.

Influence of plant growth regulators on in vitro biomass production and biosynthesis of cytotoxic Amaryllidaceae alkaloids in Caliphuria tenera Baker

Plants of the Amaryllidoideae subfamily are characterized by the presence of isoquinoline alkaloids called Amaryllidaceae alkaloids. These compounds have exhibited a broad spectrum of pharmacological effects, including anti-Alzheimer and anti-cancer. In this study, Caliphruria tenera Baker, Amaryllidaceae, an endangered and endemic species, was selected to evaluate the effect of growth regulators on plant micropropagation, biomass increase, and production of cytotoxic alkaloids. Different growth regulators were used individually and mixed, and the Amaryllidaceae alkaloids were identified and quantified by GC-MS. The maximum number of in vitro shoots (4.8) was recorded with 6-benzylaminopurine (BAP) (1 mg/L) + Kinetin (KIN) (1 mg/L) + Naphthaleneacetic acid (NAA) (0.2 mg/L). In addition, nineteen alkaloids were identified as crinine, galantamine, lycorine, narciclasine, and tazzetine-type alkaloids in cultivated and micropropagated plants. In general, the biomass was maximized with the growth hormone combination BAP + KIN + NAA, but the biosynthesis of alkaloids was minimized. However, the combination BAP + NAA showed the greatest productivity of trisphaeridine (632.01 μg/g). The growth regulators showed also a positive effect on the production of lycorine-type alkaloids with a content of 396.33 μg/g for KIN, 142.38 μg/g for BAP, and 41.67 μg/g for NAA. All alkaloid fractions were evaluated for their antiproliferative effects against human lung carcinoma (A549) and human keratinocytes (HaCat) cells. The alkaloids produced in the BAP + NAA treatment present a potent and selective cytotoxic against the A549 cell line at 30 μg/mL. This study shows that micropropagation is a promising approach for the production of cytotoxic Amaryllidaceae alkaloids in C. tenera without affecting natural populations.

Growth regulators on the shooting and rooting of Tamarix chinensis stem cuttings

Tamarisk (Tamarix chinensis) is a halophyte that plays a critically important role in the restoration of saline land. It reproduces via seeds, but the germination rate of seeds is low in its natural environment, which greatly limits its ability to spread. Vegetative propagation is a useful method for enhancing the quality and reproduction of plants, and the effects of growth regulators on stem cuttings vary. Here, we evaluated the effects of different concentrations (0, 100, 250, 500, 1,000, 1,500, 2,000, and 3000 mg L−1) of gibberellin A3 (GA), indole-3-butyric acid (IBA), naphthaleneacetic acid (NAA), and 6-benzylamine purine (BAP) on the survival, shoots, and root formation of tamarisk stem cuttings. The survival of tamarisk stem cuttings was 100% in the 100 mg L−1 GA, 1000 mg L−1 IBA, and 500 mg L−1 BAP treatments. The highest number of new shoots per cutting was observed in the 1000 mg L−1 IBA treatment and three times higher than in the control (0 mg L−1; CK), only significant difference with the 250 mg L−1 NAA treatment. The fresh weight of the shoots and roots was higher in the 100 mg L−1 GA, 1000 mg L−1 IBA, 500 mg L−1 BAP, and 250 mg L−1 NAA treatments, and was 161%, 200%, 114%, 66% and 150%, 300%, 150%, 183% higher than in the CK, respectively. Although, the fresh weight of the shoots and roots was highest in the 1000 mg L−1 IBA treatment, it is only significantly differed from that in the 500 mg L−1 BAP and 250 mg L−1 NAA treatments in the fresh weight of the shoots. No significant differences in root length and diameter were observed in the 100 mg L−1 GA, 1000 mg L−1 IBA, 500 mg L−1 BAP, and 250 mg L−1 NAA treatments. Root surface area and volume were significantly higher in the 250 mg L−1 NAA treatment than in the 1000 mg L−1 IBA and 500 mg L−1 BAP treatments. Overall, growth regulators significantly affected the shooting and rooting ability of tamarisk stem cuttings. The following treatments were the most effective for enhancing the quality of tamarisk stem cuttings: 100 mg L−1 GA, 1000 mg L−1 IBA, 500 mg L−1 BAP, and 250 mg L−1 NAA. The growth of tamarisk stem cuttings was maximized in the 1000 mg L−1 IBA treatment, and the survival of tamarisk stem cuttings was lowest in the 250 mg L−1 NAA treatment. This study provides a theoretical basis and data support for the technology of growth regulators on the shooting and rooting of tamarisk stem cuttings.

Transcriptome and metabolome profiling unveils the mechanisms of naphthalene acetic acid in promoting cordycepin synthesis in Cordyceps militaris.

Cordycepin, an important active substance in Cordyceps militaris, possesses antiviral and other beneficial activities. In addition, it has been reported to effectively promote the comprehensive treatment of COVID-19 and thus has become a research hotspot. The addition of naphthalene acetic acid (NAA) is known to significantly improve the yield of cordycepin; however, its related molecular mechanism remains unclear. We conducted a preliminary study on C. militaris with different concentrations of NAA. We found that treatment with different concentrations of NAA inhibited the growth of C. militaris, and an increase in its concentration significantly improved the cordycepin content. In addition, we conducted a transcriptome and metabolomics association analysis on C. militaris treated with NAA to understand the relevant metabolic pathway of cordycepin synthesis under NAA treatment and elucidate the relevant regulatory network of cordycepin synthesis. Weighted gene co-expression network analysis (WGCNA), transcriptome, and metabolome association analysis revealed that genes and metabolites encoding cordycepin synthesis in the purine metabolic pathway varied significantly with the concentration of NAA. Finally, we proposed a metabolic pathway by analyzing the relationship between gene-gene and gene-metabolite regulatory networks, including the interaction of cordycepin synthesis key genes; key metabolites; purine metabolism; TCA cycle; pentose phosphate pathway; alanine, aspartate, and glutamate metabolism; and histidine metabolism. In addition, we found the ABC transporter pathway to be significantly enriched. The ABC transporters are known to transport numerous amino acids, such as L-glutamate, and participate in the amino acid metabolism that affects the synthesis of cordycepin. Altogether, multiple channels work together to double the cordycepin yield, thereby providing an important reference for the molecular network relationship between the transcription and metabolism of cordycepin synthesis.

EFFECT OF AUXINS ON PROPAGATION OF HONEY CROP: STEVIA REBAUDIANA (BERTONI) BERTONI.

The present study was conducted to optimize the green house conditions for Propagation of Stevia rebaudiana cuttings. Stevia rebaudiana belonging to the family Asteraceae, is a native to the Brazil and Paraguay. Its leaves produced stevioside, an a caloric natural sweetener. The sweetness of stevioside was 150 -300 times greater than sucrose. Seeds of Stevia were very small in size. Production of Stevia through seeds was not beneficial because seeds were not viable for germination due to their infertility. In present study different concentrations of Naphthalene acetic acid (NAA) and Indole Butyric acid (IBA) were used to study their effect on the rooting of Stevia rebaudiana cuttings. Results showed that highest number of roots per cutting were observed to be 34.9 from 3% NAA solution, showing maximum root length, root number, shoot length and number of nodes per cutting. Cuttings of Stevia rebaudiana responded well in NAA treatment as compared to the IBA treatment. It was concluded that Naphthalene acetic acid was a better choice for enhanced rooting and vegetative propagation of Stevia rebaudiana through stem cuttings.

Physical and Chemical Properties of Pineapple Fruit of cv. Pada and cv. Sarawak in Response to Flowering Hormones

Pineapple flowering can be stimulated through artificially induced flowering (AIF) to ensure year-round production. The post effect gains from AIF is currently not universally acknowledged by previous studies, therefore, this study aims to evaluate the physical and chemical fruit properties in response to different AIF practices on cv. Pada, and cv. Sarawak. The AIF was applied to 9-month-old plants with nine treatments being tested, consisting of calcium carbide (CaC2), naphthaleneacetic acid (NAA), and ethephon at various concentrations. The fruit samples were collected at a maturity index of 5 in order to determine its physical (total fruit weight, fruit weight without crown, total fruit length, fruit length without crown, fruit diameter, peduncle length and peduncle diameter) and chemical properties (pH, total soluble solid and titratable acidity). The results showed that the total fruit weight as well as fruit weight without crown on cv. Pada and total fruit weight on cv. Sarawak were not affected by AIF treatments. The study showed a significantly higher fruit weight in T7 (low ethephon concentration) in comparison to T10 (high ethephon concentration) and T4 (NAA treatment) was recorded on cv. Sarawak. The trend of fruit length without crown on both cultivars decreased as the hormone concentration increased. The peduncle length exhibited significantly shorter in T3 (high CaC2 concentration) for cv. Pada, and T10 (high ethephon concentration) for cv. Sarawak at 30%, and 15% shorter than other treatments, respectively. In fruit chemical properties, TSS and TA on cv. Pada showed a significant difference, this particular result may have been influenced by an external factor such as the environmental conditions during the fruit ripening stage due to differing harvesting periods between the treatments. Overall, the study suggests that the AIF treatments may affect some of the physical and chemical fruit properties either via the direct or indirect response toward AIF.

Transcriptome analysis reveals the regulatory mode by which NAA promotes the growth of Armillaria gallica.

A symbiotic relationship is observed between Armillaria and the Chinese herbal medicine Gastrodia elata (G. elata). Armillaria is a nutrient source for the growth of G. elata, and its nutrient metabolism efficiency affects the growth and development of G. elata. Auxin has been reported to stimulate Armillaria species, but the molecular mechanism remains unknown. We found that naphthalene acetic acid (NAA) can also promote the growth of A. gallica. Moreover, we identified a total of 2071 differentially expressed genes (DEGs) by analyzing the transcriptome sequencing data of A. gallica at 5 and 10 hour of NAA treatment. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses showed that these unigenes were significantly enriched in the metabolism pathways of arginine, proline, propanoate, phenylalanine and tryptophan. The expression levels of the general amino acid permease (Gap), ammonium transporter (AMT), glutamate dehydrogenase (GDH), glutamine synthetase (GS), Zn(II) 2Cys6 and C2H2 transcription factor genes were upregulated. Our transcriptome analysis showed that the amino acid and nitrogen metabolism pathways in Armillaria were rapidly induced within hours after NAA treatment. These results provide valuable insights into the molecular mechanisms by which NAA promotes the growth of Armillaria species.

Integrated transcriptome and hormonal analysis of naphthalene acetic acid-induced adventitious root formation of tea cuttings (Camellia sinensis)

BackgroundTea plant breeding or cultivation mainly involves propagation via cuttings, which not only ensures the inheritance of the excellent characteristics of the mother plant but also facilitates mechanized management. The formation of adventitious root (AR) determines the success of cutting-based propagation, and auxin is an essential factor involved in this process. To understand the molecular mechanism underlying AR formation in nodal tea cuttings, transcriptome and endogenous hormone analysis was performed on the stem bases of red (mature)- and green (immature)-stem cuttings of ‘Echa 1 hao’ tea plant as affected by a pulse treatment with naphthalene acetic acid (NAA).ResultsIn this study, NAA significantly promoted AR formation in both red- and green-stem cuttings but slightly reduced callus formation. External application of NAA reduced the levels of endogenous indole-3-acetic acid (IAA) and cytokinin (TZR, trans-zeatin riboside). The number of DEGs (NAA vs. CK) identified in the green-stem cuttings was significantly higher than that in the red-stem cuttings, which corresponded to a higher rooting rate of green-stem cuttings under the NAA treatment. A total of 82 common DEGs were identified as being hormone-related and involved in the auxin, cytokinin, abscisic acid, ethylene, salicylic acid, brassinosteroid, and jasmonic acid pathways. The negative regulation of NAA-induced IAA and GH3 genes may explain the decrease of endogenous IAA. NAA reduced endogenous cytokinin levels and further downregulated the expression of cytokinin signalling-related genes. By the use of weighted gene co-expression network analysis (WGCNA), several hub genes, including three [cellulose synthase (CSLD2), SHAVEN3-like 1 (SVL1), SMALL AUXIN UP RNA (SAUR21)] that are highly related to root development in other crops, were identified that might play important roles in AR formation in tea cuttings.ConclusionsNAA promotes the formation of AR of tea cuttings in coordination with endogenous hormones. The most important endogenous AR inductor, IAA, was reduced in response to NAA. DEGs potentially involved in NAA-mediated AR formation of tea plant stem cuttings were identified via comparative transcriptome analysis. Several hub genes, such as CSLD2, SVL1 and SAUR21, were identified that might play important roles in AR formation in tea cuttings.

Clonal Propagation of Valeriana jatamansi Retains the Essential Oil Profile of Mother Plants: An Approach Toward Generating Homogenous Grade of Essential Oil for Industrial Use.

Valeriana jatamansi Jones (Syn. V. wallichii DC.) is an aromatic, medicinal herb used as a tranquilizer and in treating sleep disorders. Rhizome is mainly used to extract essential oil (EO) and valepotriates. High quality and economic yield of rhizomes are available in the third year of growth. Therefore, the cultivation of V. jatamansi is not picking up, and over-exploitation of this plant from wild habitats to meet the increasing demand of the pharmaceutical industry is the cause of threat to the genetic diversity of the species. Further, collections from the wild are heterogeneous, resulting in variable produce. The development of clonal lines can ensure uniform quality and yield of rhizome biomass. An effective clonal propagation method was standardized using different hormonal concentrations of naphthalene acetic acid (NAA) on apical shoot cuttings from the selected clone CSIR-IHBT-VJ-05 for different time durations and raised over various planting media. NAA treatment of 50 ppm concentration for 30 min was found optimum for root induction in apical shoots of V. jatamansi. Variations for EO composition within the clone were non-significant, while samples of the control population were variable. The best quality EO (patchouli alcohol ∼62%) was available during the third year of plant growth. A propagation technique for large-scale quality plant material (QPM) production has been standardized to reduce the stress over natural resources and promote V. jatamansi for use in the aromatic and pharmaceutical industry.

The Effect of Different Levels of Indole-3-butyric Acid (IBA) and Naphthaleneacetic acid (NAA) on the Rooting of The Effect of Different Levels of Indole-3-butyric Acid (IBA) and Naphthaleneacetic acid (NAA) on the Rooting of Pear Stem CuPear Stem Cutting

The Effect of Different Levels of Indole-3-butyric Acid (IBA) and Naphthaleneacetic acid (NAA) on the Rooting of The Effect of Different Levels of Indole-3-butyric Acid (IBA) and Naphthaleneacetic acid (NAA) on the Rooting of Pear Stem CuPear Stem Cutting

Systematic analysis of specific and nonspecific auxin effects on endocytosis and trafficking.

The phytohormone auxin and its directional transport through tissues are intensively studied. However, a mechanistic understanding of auxin-mediated feedback on endocytosis and polar distribution of PIN auxin transporters remains limited due to contradictory observations and interpretations. Here, we used state-of-the-art methods to reexamine the auxin effects on PIN endocytic trafficking. We used high auxin concentrations or longer treatments versus lower concentrations and shorter treatments of natural indole-3-acetic acid (IAA) and synthetic naphthalene acetic acid (NAA) auxins to distinguish between specific and nonspecific effects. Longer treatments of both auxins interfere with Brefeldin A-mediated intracellular PIN2 accumulation and also with general aggregation of endomembrane compartments. NAA treatment decreased the internalization of the endocytic tracer dye, FM4-64; however, NAA treatment also affected the number, distribution, and compartment identity of the early endosome/trans-Golgi network, rendering the FM4-64 endocytic assays at high NAA concentrations unreliable. To circumvent these nonspecific effects of NAA and IAA affecting the endomembrane system, we opted for alternative approaches visualizing the endocytic events directly at the plasma membrane (PM). Using total internal reflection fluorescence microscopy, we saw no significant effects of IAA or NAA treatments on the incidence and dynamics of clathrin foci, implying that these treatments do not affect the overall endocytosis rate. However, both NAA and IAA at low concentrations rapidly and specifically promoted endocytosis of photo-converted PIN2 from the PM. These analyses identify a specific effect of NAA and IAA on PIN2 endocytosis, thus, contributing to its polarity maintenance and furthermore illustrate that high auxin levels have nonspecific effects on trafficking and endomembrane compartments.

Assessing Impact of Naphthalene Acetic Acid on the Growth and Yield of Okra (Abelmoschus esculentus (L.) Moench)

This study assessed the impact of naphthalene acetic Acid (NAA) on the growth and yield of Okra cv. Sabz Pari at Agricultural Research Institute, Dera Ismail Khan, Khyber Pakhtunkhwa, Pakistan. A field experiment was set out in randomised complete block design with NAA application as a main factor. Different NAA concentrations were obtained by dissolving NAA in distilled water at the rate of 0 (control), 10, 30, 50, 70, 90 and 110 mg/L. NAA treatments along with control were foliar applied to okra plants after 30 days of sowing. Lower concentration of NAA (30-50 mg/L) stimulated maximum increase in plant height (59.5-57.2%), number of leaves/plant (50.4-45.5%,), total plant leaf area (113.9-119.4%), internodes/plant (72.5-61.6%), internode length (53.2-44.5%), pod diameter (53.5-49.9%), pod fresh weight (126.8-111.8%), pod yield (271.2-255.8%) compared to control (0 mg NAA/L). NAA at higher concentrations (>50 mg/L) had a supressing effect on most parameters. It was inferred that yield production in okra is influenced by multiple yield-determining component traits and their mutual interactions which could be manipulated by the application of NAA. Foliar application of NAA (30-50 mg/L) have a beneficial impact on plant characters and yield of Okra, hence recommended in Okra cultivation.
 

Influence of NAA on root promotion in vegetative propagation of Duranta erecta L.

The current study was aimed to find the effect of NAA on rooting of cuttings in Duranta erecta L. The experiment was laid out in Completely Randomized Block Design (CRD) with 3 replications, including six treatments of various concentration of Naphthalene Acetic Acid (NAA) solutions viz., 250 ppm, 500 ppm, 1000 ppm, 2000 ppm, 3000 ppm and control (without any treatment). Minimum days for sprouting (11.52 days), rooting percentage (85.63%), number of roots per cutting (8.15) and root length (9.56 cm) are recorded maximum NAA 3000 ppm. All the NAA treatments are on par with each other and significantly higher than control in survival percentage. From this experiment we conclude that, the rooting and survival capacity of hardwood stem cuttings of Duranta erecta under mist chamber conditions, can be improved by quick dipping of basal portion of cuttings on NAA with 3000 ppm concentration.

<p>Influence of naphthalene acetic acid on fruit setting, fruit quality and yield of <em>Manilkara achras</em> L. cv. <em>Kalipatti</em> under subtropical conditions</p>

Manilkara achras L., commonly called sapota, is one of the major fruit crops commercially grown in India. Though India leads in world sapota production, the major problems in sapota are low fruit setting and yield. Hence, we studied these aspects in the commercially grown sapota cv. Kalipatti in Punjab conditions. The experiment was conducted to standardize the doses of naphthalene acetic acid (NAA) for fruit setting, quality and yield of sapota at Punjab Agricultural University, Ludhiana during 2016 and 2017. The results revealed that foliar application of 100 ppm NAA at flowering and pea stage during May flowering resulted in higher fruit setting (4.9%) and higher fruit retention (83.5%) over other treatments including control. Similarly, higher fruit setting (18.5%) and higher fruit retention (88.5%) and higher yield (75.90 kg/tree) were recorded in July-August flowering with foliar application of 100 ppm NAA. Fruit quality in terms of average fruit weight (104 g), TSS (22.50 oBrix) and acidity (0.20%) was also higher in 100 ppm NAA foliar application. Significantly lower PLW (7.56%) was also recorded in 100 ppm NAA treatment. Furthermore, it was observed that profuse flowering occurred during May, July and August months but the later flowering resulted in better crop. The study concluded that fruit setting, quality and yield in sapota cv. Kalipatti can be enhanced through foliar application of 100 ppm NAA at flowering and pea stage during July-August flowering under subtropical conditions.