ACC was applied during cool conditions, but high temperatures should be avoided. Literature Cited Adams, D.O. Yang, S.F. 1979 Ethylene biosynthesis: Identification of 1-aminocyclopropane-1-carboxylic acid as an intermediate in the conversion of
Ethylene production of tissues excised from root, stem, leaf, inflorescence, and fruit of 16 plant species greatly increased following the application of 1-aminocyclopropane-1 carboxylic acid (ACC), an intermediate in the conversion of methionine to ethylene. Treatment with 1 mM ACC invariably increased the rate of ethylene production 10 to 1000 times over controls, whereas methionine at the same concentration was ineffective. Treatment with 0.1 mM ACC consistently increased ethylene production in all of the tissues tested, although only a few tissues responded to 0.01 mM.
Changes in the level of 1-aminocyclopropane-1-carboxylic acid (ACC) were compared to ethylene production during fruit ripening of avocado (Persea americana Mill.) banana (Musa sapientum L.) and tomato (Lycopersicon esculentum Mill.). Preclimacteric tissues contained less than 0.1 nmol/g of ACC in all tissues. In avocado, the level of ACC increased to 45 nmol/g in the later stage of the climacteric rise, then decreased to 5 nmol/g, and later increased to over 100 nmol/g in overripe fruit. In banana ACC increased to 5 nmol/g during the climacteric, decreased to 2 nmol/g several days after the climacteric peak, and increased up to 5 nmol/g in overripe fruit. Levels of ACC in tomato ranged from 0.1 to 10 nmol/g and were significantly correlated with ethylene production rates in all but overripe fruits. The correlation between the ACC content and the production of ethylene is discussed.
Petunia hybrida pollen accumulates significant levels of the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC) late in development. This pollen ACC is thought to play a role in the rapid burst of ethylene produced by pollinated pistils. To investigate this further, we have expressed the ACC deaminase gene product from Pseudomonas in transgenic petunias under the control of three different promoters including CaMV-35S, LAT52, and TA29 directing construction expression, pollen-specific expression and tapetum-specific expression, respectively. Several transgenic plants expressing the LAT52-ACC deaminase gene exhibited significant reduction of ACC in pollen. Two independent transformants contained only trace amounts of ACC in pollen. In contrast, the other promoters did not lead to reduced ACC in pollen. Pollination of wild-type pistils with pollen from LAT52-ACC deaminase plants elicited increased ethylene similar to wild-type pollen. Fecundity was unaffected by the reduction in pollen ACC content. Taken together, we conclude pollen-borne ACC is not the elicitor of pollination-induced ethylene production by pistils.
1-aminocyclopropane-1-carboxylic acid (ACC) sprays on 0, 9, and 14 d after treatment (8 Aug. 2013) in Parlier, CA. Before treatment, berry weights ranged from 1.61 to 1.71 g/berry, soluble solids averaged about 23%, and titratable acidity ranged from
Mature pollen from Petunia hybrida contains significant levels of 1-aminocyclopropane-1-carboxylic acid (ACC), and this ACC is thought to play a role in pollination-induced ethylene by the pistil. We investigated the developmental accumulation of ACC in anthers and pollen. The level of ACC in anthers was very low until the day before anthesis, at which time it increased 100-fold. A 1.1-kb partial ACC synthase cDNA clone (pPHACS2) was amplified from total RNA isolated from mature anthers by reverse transcriptase, followed by polymerase chain reaction using oligonucleotide primers synthesized to conserved amino acid sequences in ACC synthases. The expression of pPHACS2 mRNA during anther development was correlated with the accumulation of ACC and was localized to the pollen grain. The pPHACS2 cDNA was used to identify the PH-ACS2 gene from a library of genomic DNA fragments from Petunia hybrida. PH-ACS2 encoded an ACC synthase transcript of four exons interrupted by three introns. The ACC synthase protein encoded by the PH-ACS2 gene shared >80% homology with ACC synthases from tomato (LE-ACS3) and potato (ST-ACS1a). A chimeric PH-ACS2 promoter-β-glucuronidase (GUS) gene was used to transform petunia and transgenic plants were analyzed for GUS activity. GUS staining was localized to mature pollen grains and was not detected in other tissues. Despite similarities to LE-ACS3, we did not detect GUS activity under conditions of anaerobic stress or in response to auxin. A series of 5-prime-flanking DNA deletions revealed that sequences within the PH-ACS2 promoter were responsible for pollen-specific expression.
The changes in ethylene production rates and development of 1-aminocyclopropane-l-carboxylic acid (ACC) synthase and polygalacturonase (PG) activities were studied during the maturation and ripening of tomato fruit (Lycopersicon esculentum Mill, cv. ‘Castlemart’). There was a linear relationship between internal ethylene concentration and ethylene production rate; both increased exponentially as tomato fruit reached more advanced maturity and ripening. Thus, both of them correlate with the maturity and the ripening stages of tomatoes. A small increase in ACC synthase activity was observed at the early mature green stages which was followed by a marked increase at the breaker stage. ACC level followed the same pattern as ACC synthase activity. PG activity was undetectable or low throughout the mature green stages, but increased significantly after reaching the breaker stage. These data indicate that the onset of the development of ACC synthase activity precedes that of PG activity.
A tissue culture screen for ethylene tolerance using 1-aminocyclo-propane-1-carboxylic acid (ACC) was optimized for a snapdragon (Antirrhinum majus) inbred line, OAK564. Two experiments were conducted using various concentrations of ACC (ranging from 0 to 100 μM). Presence of 5 μM ACC in the tissue culture medium elucidated biological activity in snapdragon seeds. This screen was used to determine relative sensitivity to ethylene in 48 hybrid lines. Different levels of sensitivity to ethylene were observed among the various hybrid lines. Moreover, 40,000 mutagenized seeds from three M2 populations, derived from different levels of EMS (0.5%, 0.75%, and 1.0%) treatments, were screened for ethylene sensitivity. A total of 231 putative mutants were recovered spanning eight distinct phenotypes based on the `triple response' assay. Of these putative mutants, 16 mutants were selected for further analysis, including at least one and up to three lines from each of the eight phenotypic classes. Plants were established in the greenhouse, and allowed to grow to maturity to collect selfed seeds. These seeds were once again screened with 5 μM ACC to determine the level of ethylene sensitivity present within each of the eight phenotypic classes. Responses in the M3 populations varied from complete ethylene tolerance to ethylene sensitivity. Implications of these results on the recovery of ethylene tolerant mutants will be discussed.
`Testarossa' gerbera (Gerbera jamesonii Bolus) scapes were injected with distilled water (control), or 0.3, 0.6, and 0.9 mm ACC at harvest, then held at 20 °C for 15 days in a preservative solution. PAL activity and ethylene production increased within 1 day proportionally to injected ACC. ACC injection reduced bending incidence, inhibited flower scape elongation, enhanced firmness of the flower scapes and increased vase life. Flower scapes treated with ACC reached full maturity 3 days before the end of vase life of the control, which bent before reaching full maturity.
Firmness loss, increase in 1-aminocyclopropane-l-carboxylic acid (ACC) concentrations, and increase in internal ethylene concentrations were greatest in airstored fruit of ‘Golden Delicious’ apple (Malus domestica Borkh.) and lowest in controlled-atmosphere (CA)-stored fruit receiving a “rapid CA” or a “prestorage high carbon dioxide” storage procedure. Changes in apples kept in “slow CA” were intermediate. The accumulation of ACC in fruit was related closely to the subsequent flesh softening and increase in internal C2H4 concentration, and these processes were suppressed to different degrees in CA-stored fruit, depending on the storage procedures.