scholarly journals NAA-induced Ethylene and ACC in `Delicious' Spur Tissues: Changes with Temperature and Time

1991 ◽  
Vol 116 (5) ◽  
pp. 846-850 ◽  
Author(s):  
Eric A. Currv
Keyword(s):  
Acetic Acid ◽  
Malus Domestica ◽  
Ethylene Production ◽  
Leaf Tissue ◽  
Ethylene Evolution ◽  
Fruit Abscission ◽  
Fruit Drop ◽  
June Drop

These studies with apple (Malus domestica Borkh.) spur tissues were conducted to investigate the mechanism whereby NAA may stimulate fruit abscission in the spring but acts to prevent fruit drop in the fall. NAA-induced ethylene evolution from `Delicious' spurs in vivo was similar to that evolved from excised leaf and fruit tissues that later were treated in the laboratory and incubated in darkness at 20C. The peak in ethylene production occurred 24 hours after treatment at 30C, 48 hours after treatment at 20C, and production was still increasing 72 hours after treatment at 10C. Leaf tissue showed the greatest induction of ethylene from NAA followed by fruit and petiolar tissues. Induction was greatest early in the season and declined steadily until about “June drop.” After this time, none of the tissues showed significant capacity for ethylene induction. Chemical names used: 2-(1 -naphthyl) acetic acid (NAA).

scholarly journals Reduction of Early Fruit Abscission by Main-branch-girdling in Macadamia Is Related to the Favorable Status of Carbohydrates and Endogenous Hormones

HortScience ◽  
2022 ◽  
Vol 57 (1) ◽  
pp. 40-47
Author(s):  
Wei Hai Yang ◽  
Chao Zhong Lu ◽  
Wei Chen ◽  
Huan Yu Xu
Keyword(s):  
Acetic Acid ◽  
Fruit Set ◽  
Physiological Mechanism ◽  
Zeatin Riboside ◽  
Endogenous Hormones ◽  
Fruit Abscission ◽  
Fruit Drop ◽  
Macadamia Integrifolia ◽  
Horticultural Practice ◽  
Indole 3 Acetic Acid

Fruit abscission occurring severely in the early fruit development affects macadamia yield. Developing effective methods to improve fruit retention is a priority for macadamia cultivation and production. Girdling is an important horticultural practice that has been widely used to increase fruit yield. Previous studies have shown that girdling fails to increase macadamia yield despite enhancing the early fruit set, but few have examined the effect of girdling on its related physiological mechanism. The objective of this study was to investigate the effects of main-branch girdling (MBG) on early fruit retention and also on the levels of carbohydrates and endogenous hormones in the leaves, bearing shoots and fruit of macadamia. Herein, MBG was performed at fruit set using a single-blade knife on 9-year-old macadamia trees (Macadamia integrifolia). Results showed that MBG significantly reduced young fruit drop, concurrent with significant increases in the contents of starch in both the leaves and the bearing shoots and in glucose, fructose, and sucrose levels in the husk and seed. It was suggested that the availability of carbohydrate for fruit retention was improved by MBG. Additionally, MBG increased indole-3-acetic acid (IAA), gibberellin (GA3), and zeatin-riboside (ZR, a type of cytokinin) concentrations and decreased abscisic acid (ABA) contents in the husk and the seed, indicating that MBG reduced the early fruit drop by modifying the balance of endogenous hormones. Therefore, a positive interplay between carbohydrates and endogenous hormones induced by MBG was involved in the reduction of early fruit abscission in macadamia.

scholarly journals Inhibition of Softening by Polyamine Application in `Golden Delicious' and `McIntosh' Apples

1991 ◽  
Vol 116 (5) ◽  
pp. 813-817 ◽  
Author(s):  
George F. Kramer ◽  
Chien Yi Wang ◽  
William S. Conway
Keyword(s):  
Malus Domestica ◽  
Ethylene Production ◽  
Cell Walls ◽  
Chilling Injury ◽  
Ethylene Evolution ◽  
Pressure Infiltration ◽  
Golden Delicious ◽  
Water Treated Control

Pressure infiltration of `Golden Delicious' and `McIntosh' apples (Malus domestica Borkh.) with polyamides resulted in an immediate increase in firmness. `Golden Delicious' apples were 2.7 N (0.25 mM spermidine) to 6.7 N (1.0 mM spermine) firmer, while `McIntosh' apples were 2.2 N (0.25 mM spermidine) to 5.3 N (1.0 mM spermine) firmer than the water-treated control. During 28 weeks of storage at 0C, the differences between the polyamine-treated and water-treated apples were even larger. Similar results were observed with a 3% Ca treatment, but the Ca treatment reduced the rate of softening to a greater extent than did the polyamine treatments in `Golden Delicious'. Polyamides increased the endogenous levels of the polyamides infiltrated; however, the levels declined rapidly with time in storage. Both polyamine and Ca inhibited the development of chilling injury symptoms (brown core) in `McIntosh'. The influence of polyamines on ethylene production was negligible in both cultivars. The Ca treatment, however, inhibited ethylene evolution in `Golden Delicious'. Polyamides, thus, may affect apple softening through rigidification of cell walls rather than through interactions with ethylene metabolism.

scholarly journals Physiological Factors Affecting Response of Mature `Valencia' Orange Fruit to CMN-Pyrazole. II. Endogenous Concentrations of Indole-3-Acetic Acid, Abscisic Acid, and Ethylene

2001 ◽  
Vol 126 (4) ◽  
pp. 420-426 ◽  
Author(s):  
Rongcai Yuan ◽  
Ulrich Hartmond ◽  
Walter J. Kender
Keyword(s):  
Acetic Acid ◽  
Abscisic Acid ◽  
Ethylene Production ◽  
Abscission Zone ◽  
Endogenous Iaa ◽  
Fruit Abscission ◽  
Valencia Orange ◽  
Orange Fruit ◽  
Indole 3 Acetic Acid ◽  
Observation Period

Endogenous concentrations of IAA and ABA in the peel, pulp, seed, and abscission zone of mature `Valencia' oranges [Citrus sinesis (L.) Osbeck] were determined by high-performance liquid chromatography and enzyme-linked immunosorbent assay from early November 1998 to mid-June 1999. Ethylene production of mature `Valencia' oranges during the same period was determined by gas chromatography. IAA concentrations in the pulp and seed were three to five times lower than those in the peel over the 7-month observation period. IAA concentration in the abscission zone and peel was high from late April to mid-May, the period of less responsiveness to abscission chemicals. ABA concentration in the pulp was low over the entire observation period. ABA concentration in the abscission zone and peel was low during the less responsive period. Ethylene production was always low except for a slight increase during late December and early February. The IAA to ABA ratio was high in the fruit abscission zone during the less responsive period. Fruit detachment force of CMN-pyrazole-treated fruit was positively correlated with the ratio of endogenous IAA to ABA or endogenous IAA, but negatively to endogenous ABA in the fruit abscission zone. These data suggest the balance between IAA and ABA in the fruit abscission zone may be an important factor in determining sensitivity and thereby the response of mature `Valencia' orange fruit to abscission chemicals. Chemical names used: abscisic acid (ABA); indole-3-acetic acid (IAA); 5-chloro-3-methyl-4-nitro-1H-pyrazole (CMN-pyrazole).

scholarly journals Effect of Sprayable 1-MCP, AVG, and NAA on Ethylene Biosynthesis, Preharvest Fruit Drop, Fruit Maturity, and Quality of ‘Delicious’ Apples

HortScience ◽  
2008 ◽  
Vol 43 (5) ◽  
pp. 1454-1460 ◽  
Author(s):  
Rongcai Yuan ◽  
Jianguo Li
Keyword(s):  
Ethylene Production ◽  
Acc Oxidase ◽  
Acc Synthase ◽  
Naphthaleneacetic Acid ◽  
Fruit Softening ◽  
High Concentration ◽  
Oxidase Gene ◽  
Fruit Abscission ◽  
Fruit Drop ◽  
Significant Difference

Effects of naphthaleneacetic acid (NAA), aminoethoxyvinylglycine (AVG), and sprayable 1-methylcyclopropene (1-MCP) alone or in combination on fruit ethylene production, preharvest fruit drop, fruit quality, and fruit maturation were examined in ‘Delicious’ apples (Malus ×domestica Borkh.). 1-MCP and AVG + NAA, when applied 15 days before anticipated harvest (DBAH) for untreated control trees, more effectively delayed preharvest fruit drop than AVG or NAA used alone. However, there was no significant difference in ethylene production between fruit treated with 1-MCP or AVG + NAA and those treated by AVG. Two applications of NAA increased fruit ethylene production and fruit softening, whereas AVG inhibited NAA-enhanced fruit ethylene production and fruit softening. There was no significant difference in fruit ethylene production, fruit firmness, and fruit drop control between one and two applications of 1-MCP. The concentrations of 1-MCP did not affect the efficacy of 1-MCP when applied 15 DBAH, but high concentration of 1-MCP more effectively delayed preharvest fruit drop than low concentration of 1-MCP when applied 7 DBAH. Both AVG and 1-MCP suppressed expression of 1-aminocyclopropane-1-carboxylate (ACC) synthase gene MdACS1, ACC oxidase gene MdACO1, and polygalacturonase gene MdPG1 in fruit. Expression of ACS5A and MdACO1 but not MdACS1 in fruit abscission zones was decreased by AVG and 1-MCP. 1-MCP more effectively suppressed expression of MdPG2 in fruit abscission zones than AVG alone.

scholarly journals ANTI-INFLAMMATORY ACTIVITY OF CURCUMIN AND CAPSAICIN AUGMENTED IN COMBINATION

2017 ◽  
Vol 9 (6) ◽  
pp. 145
Author(s):  
Thriveni Vasanth Kumar ◽  
Manjunatha H. ◽  
Rajesh Kp
Keyword(s):  
Acetic Acid ◽  
Protective Effect ◽  
Vascular Permeability ◽  
Diclofenac Sodium ◽  
Significant Inhibition ◽  
Inflammatory Activity ◽  
Anti Inflammatory ◽  
The Individual

Objective: Dietary curcumin and capsaicin are well known for their health beneficial potencies. The current study was done to assess the anti-inflammatory activity of curcumin, capsaicin and their combination by employing in vitro and in vivo models.Methods: We investigated the protective effect of curcumin, capsaicin and their combination using in vitro heat induced human red blood cell (HRBC) membrane stabilisation, in vivo 3% agar induced leukocyte mobilisation and acetic acid induced vascular permeability assay.Results: Curcumin, capsaicin and their combination exhibited concentration dependent protective effect against heat-induced HRBC membrane destabilisation, while combined curcumin and capsaicin restored 87.0±0.64 % membrane stability and it is found to be better than curcumin, capsaicin and diclofenac sodium (75.0±0.25. 72±0.9 and 80.0±0.31 %) protective effect. In agar suspension induced leukocyte mobilization assay, the combined curcumin and capsaicin had shown 39.5±1.58 % of inhibition compared to individual curcumin and capsaicin, which showed moderate inhibition of 16.0±3.14 and 21.6±2.17 % respectively. Besides, the combined curcumin and capsaicin had shown highly significant inhibition of acetic acid-induced vascular permeability in rats (62.0±3.14 %), whereas individual curcumin and capsaicin showed moderate inhibition of vascular permeability with 36.0±2.41 and 43.0±1.92 % respectively.Conclusion: This study demonstrates the significant anti-inflammatory property of combined curcumin and capsaicin at half of the individual concentration of curcumin and capsaicin.

scholarly journals The ectopic expression of Arabidopsis glucosyltransferase UGT74D1 affects leaf positioning through modulating indole-3-acetic acid homeostasis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shanghui Jin ◽  
Bingkai Hou ◽  
Guizhi Zhang
Keyword(s):  
Acetic Acid ◽  
Ectopic Expression ◽  
Leaf Angle ◽  
Kinase Substrate ◽  
Auxin Distribution ◽  
Leaf Tissues ◽  
Photosynthesis Efficiency ◽  
Indole 3 Acetic Acid

AbstractLeaf angle is an important agronomic trait affecting photosynthesis efficiency and crop yield. Although the mechanisms involved in the leaf angle control are intensively studied in monocots, factors contribute to the leaf angle in dicots are largely unknown. In this article, we explored the physiological roles of an Arabidopsis glucosyltransferase, UGT74D1, which have been proved to be indole-3-acetic acid (IAA) glucosyltransferase in vitro. We found that UGT74D1 possessed the enzymatic activity toward IAA glucosylation in vivo and its expression was induced by auxins. The ectopically expressed UGT74D1 obviously reduced the leaf angle with an altered IAA level, auxin distribution and cell size in leaf tissues. The expression of several key genes involved in the leaf shaping and leaf positioning, including PHYTOCHROME KINASE SUBSTRATE (PKS) genes and TEOSINTE BRANCHED1, CYCLOIDEA, and PCF (TCP) genes, were dramatically changed by ectopic expression of UGT74D1. In addition, clear transcription changes of YUCCA genes and other auxin related genes can be observed in overexpression lines. Taken together, our data indicate that glucosyltransferase UGT74D1 could affect leaf positioning through modulating auxin homeostasis and regulating transcription of PKS and TCP genes, suggesting a potential new role of UGT74D1 in regulation of leaf angle in dicot Arabidopsis.

Control of premature fruit drop in Macadamia integrifolia: effects of naphthalene acetic acid application, cincturing, and shoot-tip removal

1980 ◽  
Vol 20 (107) ◽  
pp. 740 ◽  
Author(s):  
RR Williams
Keyword(s):  
Acetic Acid ◽  
Fruit Set ◽  
Shoot Tip ◽  
Naphthalene Acetic Acid ◽  
Fruit Drop ◽  
Macadamia Integrifolia

The effects of NAA application, cincturing and shoot-tip removal on the incidence of premature fruit drop were investigated in orchard-grown trees of Macadamia integrifolia cv. Kakea. A single, post-anthesis application of NAA (1 ppm) increased (P < 0.05) the final set of macadamia fruit by 35%. Limb cincturing combined with shoot-tip removal increased (P < 0.05) initial fruit set and possibly final set. Cincturing alone was less effective and shoot-tip removal had no effect alone.

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