Various Stages Of Fruit Development Research Articles

Correlations among six hormone-induced transcription factors and the alcohol acyltransferase gene in apple

Alcohol acyltransferase (AAT) plays an important role in ester biogenesis in ripening fruit. In apple, MdAAT2 is up-regulated in response to treatment with defense-related hormones. We cloned a novel MdAAT2 promoter via thermal asymmetric interlaced PCR (TAIL-PCR). Sequence analysis indicated the presence of salicylic acid (SA)- and methyl jasmonate (MeJA)-responsive elements in the promoter region. To examine further the operational mechanism for transcription factors (TFs) in regulating expression of the MdAAT2 promoter, we isolated and investigated six potential stress-induced TFs — MdMYB1, MdMYB2, MdMYB6, MdERF1, MdERF2, and WRKY. These were monitored during various stages of fruit development as well as under several hormonal treatments. Reverse transcription-polymerase chain reaction (RT-PCR) analysis showed that all of these TF genes, as well as MdAAT2, were detectable in the stigmas. Levels of expression by MdMYB1, MdMYB2, and MdERF1 were significantly correlated with that by MdAAT2 during fruit ontogeny. Moreover, transcription of three TFs (MdMYB1, MdMYB6, and MdERF1) was significantly correlated with that of MdAAT2 upon exposure to ethephon, SA, or MeJA. Sequence analysis demonstrated that CAAT, CCAAT elements, and several MYB transcription factor binding sites (CNGTTmotif, AACCA, and CTAACCA elements) existed in the MdAAT2 promoter region. Using that analysis, we performed modeling of MdMYB1 and MdMYB6 based on PROTEINDNA complex1 and complex3 (PDB Accession Numbers 1H88 and 1H8A). There, similarities were found with the protein complex of CAAT or CCAAT consensus sequences. Thus, we propose that two TFs — MdMYB1 and MdMYB6 — are directly or indirectly involved in the activation of MdAAT2 expression in apple fruit.

In vitro free radical scavenging activity of aonla (Emblica officinalis) varieties at various stages of fruit development

In vitro free radical scavenging activity of aonla (Emblica officinalis) varieties at various stages of fruit development

Mining the surface proteome of tomato (Solanum lycopersicum) fruit for proteins associated with cuticle biogenesis

The aerial organs of plants are covered by the cuticle, a polyester matrix of cutin and organic solvent-soluble waxes that is contiguous with the polysaccharide cell wall of the epidermis. The cuticle is an important surface barrier between a plant and its environment, providing protection against desiccation, disease, and pests. However, many aspects of the mechanisms of cuticle biosynthesis, assembly, and restructuring are entirely unknown. To identify candidate proteins with a role in cuticle biogenesis, a surface protein extract was obtained from tomato (Solanum lycopersicum) fruits by dipping in an organic solvent and the constituent proteins were identified by several complementary fractionation strategies and two mass spectrometry techniques. Of the ∼200 proteins that were identified, a subset is potentially involved in the transport, deposition, or modification of the cuticle, such as those with predicted lipid-associated protein domains. These include several lipid-transfer proteins, GDSL-motif lipase/hydrolase family proteins, and an MD-2-related lipid recognition domain-containing protein. The epidermal-specific transcript accumulation of several of these candidates was confirmed by laser-capture microdissection and quantitative reverse transcription-PCR (qRT-PCR), together with their expression during various stages of fruit development. This indicated a complex pattern of cuticle deposition, and models for cuticle biogenesis and restructuring are discussed.

Regulation of two germin-like protein genes during plum fruit development

Germin-like proteins (GLPs) have several proposed roles in plant development and defence. Two novel genes (Ps-GLP1 and 2) encoding germin-like protein were isolated from plum (Prunus salicina). Their regulation was studied throughout fruit development and during ripening of early and late cultivars. These two genes exhibited similar expression patterns throughout the various stages of fruit development excluding two important stages, pit hardening (S2) and fruit ripening (S4). During fruit development until the ripening phase, the accumulation of both Ps-GLPs is related to the evolution of auxin. However, during the S2 stage only Ps-GLP1 is induced and this could putatively be in a H2O2-dependent manner. On the other hand, the diversity in the Ps-GLPs accumulation profile during the ripening process seems to be putatively due to the variability of endogenous auxin levels among the two plum cultivars, which consequently change the levels of autocatalytic ethylene available for the fruit to co-ordinate ripening. The effect of auxin on stimulating ethylene production and in regulating Ps-GLPs transcripts was also investigated. These data, supported by their localization in the extracellular matrix, suggest that auxin is somehow involved in the regulation of both transcripts throughout fruit development and ripening.

Altering growth and maturation of Actinidia chinensis ‘Hort16A’ fruit by heating individual berries

SummaryCuvettes that heat individual fruits on a kiwifruit vine were used to determine how the characteristics of Actinidia chinensis ‘Hort16A’ fruit are affected by temperature at various stages of fruit development. Each cuvette fitted around a single kiwifruit and a radiant heating element heated the enclosed fruit. Cuvette temperatures were controlled so that each fruit was kept about 4°C warmer than ambient fruit. Heating individual fruit during the early, mid and late periods of the growing season was found to have some immediate effects, and also effects that persisted until harvest. There was an immediate effect on fruit growth, which was most marked early in the season, and which resulted in larger fruit at harvest. Also, heating fruit early in the season increased the soluble solids content at harvest, as well as inducing more yellow (lower hue angle) and softer fruit at harvest. Heating fruit just prior to harvest increased their final dry matter concentration.

Xanthoxin, abscisic acid and its metabolite levels associated with apple fruit development

A suitable internal standard for the measurement of natural xanthoxin (XAN) was developed. Endogenous XAN, abscisic acid (ABA), phaseic acid (PA), dihydrophaseic acid (DPA), and epi-dihydrophaseic acid (epi-DPA) concentrations were quantified in the pulp and seeds of apples in various stages of fruit development. The relative amounts of ABA in the pulp increased toward fruit maturation. On a molar basis, the amount of total XAN (cis, trans-XAN and trans, trans-XAN) in immature fruit was equal to the amount of ABA. However during the fruit ripening process, the total XAN levels markedly decreased in proportion with increases in the levels of ABA. At the climacteric rise and postclimacteric stage ABA concentrations were higher than the total amount of XAN. The low levels of XAN in a ripening apple may be caused by its rapid turnover. The total XAN concentrations was high in immature seeds but decreased toward seed maturation. The opposite tendency was observed in the case of ABA concentration. Thus, decreases of total XAN correlated with increases in the ABA levels; this tendency was observed in both the pulp and seeds, and was consistent with the role of XAN as an ABA precursor. In the pulp, PA concentrations changed in a manner similar to those of ABA. The maximum epi-DPA concentration was 67% of the maximum ABA concentration, but the maximum DPA concentration was only 11% of the maximum ABA concentration. Therefore, epi-DPA may be a major metabolite of PA in the pulp. In contrast, DPA appeared to be the major metabolite of ABA in apple seeds, because the levels of DPA were higher than those of PA and epi-DPA.

Hormonal Interactions in Fruit Development

Fruit development involves a complex interplay of cell division, differentiation and expansion of sporophytic and gametophytic tissues that is carefully coordinated temporally and spatially. Plant hormones are signal molecules that regulate many processes of plant development, including fruit development leading to mature fruit and viable mature seed. Auxins, gibberellins, cytokinins, abscisic acid, and ethylene have been implicated at various stages of fruit development. In the past, hormone application studies and hormone analysis studies have supported the hypothesis that fruit development is in part regulated by hormonal interaction. More recently, biochemical, genetic, and molecular studies are beginning to unravel the complexities of how hormones affect fruit development. In the current work, we review selected studies that show the interplay between hormones during fruit development, with an emphasis on the interaction between auxin and gibberellin in pea fruit development.

Activity of pectinmethylesterase, pectin content and vitamin C in acerola fruit at various stages of fruit development

In order to know which stage of fruit development is better for acerola industrialization, we studied the PME specific activity, pectin content and vitamin C at various stages of development. The acerola fruits were classified according to colour and weight in five stages: immature green (2.62–3.21 g), green (4.04–4.83 g), mature green/yellow (5.03–5.88 g), pale-red (6.16–6.77 g) and ripe mature (6.92–8.37 g). The results showed that the highest content of pectin and vitamin C occurred at the immature green stage, 4.51±0.1% yield, 2424 mg/100 g of pulp and decreased as fruit ripened, 2.99±0.03% yield, 957±0.0 mg/100 g of pulp, respectively. However, at the same stages, the values of PME specific activity were lowest, 0.61±0.01 and 0.55±0.0 units g−1/g of pulp, respectively. The highest value of PME activity was 2.08±0.01 units g−1/g of pulp in the green stage.

357 Combinations of GA3 and AVG Delay Fruit Maturity, Increase Fruit Size, and Improve Storage Life of `Feicheng' Peaches

`Feicheng' peach is a favorite cultivar in China due to is large size and high eating quality. However, its storage quality is poor and its market life is relatively short. Different combinations of AVG and GA3 applied at various stages of fruit development were evaluated to prolong market life of this fruit. A combination of 80-100 mg/L AVG and 80-100 mg/L GA3 at the end of pit hardening gave the best results. This treatment retarded the change in ground color, loss of firmness, and reduction in acidity by2 to 3 weeks. Since harvest was delayed, soluble solid content increased compared with the control that was harvested earlier. Fruit size increased significantly on treated trees. During 6 weeks of storage at 0 °C, ethylene evolution increased and fruit firmness decreased slowly in control fruit, but in AVG+GA3-treated fruit, they did not change from the low initial levels. At the end of storage, control fruit developed a high percentage (83%) of tissue browning and mealiness after warming at 20 °C for 4 days, but the AVG+GA3-treated fruit ripened normally and developed much less (16%) tissue browning and mealiness. Our results showed that the market life of `Feicheng' peaches can be prolonged by at least 4 weeks by using the AVG+GA3 treatment to delay harvest and improve storage quality.

Influence of Light on Grape Berry Growth and Composition Varies during Fruit Development

Potted `Cabernet Sauvignon' and `Pinot noir' grapevines (Vitis vinifera L.) grown in a sunlit phytotron were used to study the influence of cluster light exposure during various stages of fruit development on berry growth and composition. Clusters grown without light during berry development stages I and II, stage III, or stages I, II, and III, were compared to clusters exposed to light throughout fruit development (control). The temperature of light-exposed and nonexposed fruit was similar. The weights and diameters of berries grown without light during stages I and II, or stages I, II, and III, were similar and significantly lower than those of the control. Fruit softening in both cultivars, as well as the initiation of berry coloration, was delayed when berries were grown without light during stages I and II. Following fruit softening, berries grown without light during stages I, II, and III were lower in sugar than the control. On the final sample date, `Cabernet Sauvignon' berries grown without light during stages I, II, and III were higher in malate compared to the control. `Pinot noir' berries grown without light during stages I and II, or stages I, II, and III, were lower in malate before fruit softening, and higher in malate following fruit softening, than the control. Control berries had greater skin anthocyanins and phenolics compared to the remaining treatments. Berries grown without light during stages I and II, or stage III, were greater in anthocyanins and phenolics than fruit grown without light during stages I, II, and III. Light had no effect on fruit tartrate concentration or juice pH. Light had its greatest impact on fruit development during the initial stages of berry growth. Berry growth was reduced and ripening delayed when fruit were grown without light during stages I and II. Normal fruit development was not fully restored when these fruit were exposed to light during stage III.

Chemically Thinning Spur `Delicious' Apples with Carbaryl, NAA, and Ethephon at Various Stages of Fruit Development

Chemical fruit thinners were applied to limbs or whole trees of spur `Delicious' at various stages of fruit development as indicated by fruit diameter. Carbaryl, naphthalene acetic acid (NAA), and ethephon all reduced fruit set when applied at a fruit diameter of ≈4 to 15 mm. Fruit thinning for NAA and carbaryl, alone or combined, generally was greater when applied at an average fruit diameter of 8 mm, rather than at 4 mm. Repeated applications of NAA or carbaryl were no more effective than single applications. NAA + carbaryl applied at 9 mm was more effective than NAA applied at 4 mm followed by carbaryl at 8 mm. Applied when fruit diameter averaged 17 to 22 mm, ethephon and ethephon + carbaryl were effective fruit thinners. When applied at full bloom to ≈10 and 20 mm, the insecticides ethion and oxamyl, respectively, were effective fruit thinners.

Effect of spray volume and time of NAA application on fruit size and cropping of Redchief ‘Delicious’ apple

The effect of naphthaleneacetic acid (NAA) thinning sprays on fruit size of Redchief ‘Delicious’ apple was studied in relation to spray application volume and time of application. A constant dose of NAA resulted in similar fruit size at harvest when applied in varying spray volumes from high (near full retention, V x ) to V x 8 . NAA applied as a high volume spray (15 mg l −1) at various stages of fruit development (4.6 to 22.5 mm king fruit diameter, KFD), indicated that the maximum amount of small fruit was produced following applications at about 11 mm KFD. NAA did not consistently affect growth rate of king fruit immediately after treatment when fruit competition was minimized. NAA reduced fruit size at harvest by about 11% when two competing fruits were present on the same spur, but did not significantly reduce fruit size when a single fruit was permitted to develop per spur.

The Influence of Cluster Thinning at Various Stages of Fruit Development on Flame Seedless Table Grapes

A study was conducted in 1991 and 1992 to determine the influence of cluster thinning at various stages of fruit development on Flame Seedless table grapes grown in the San Joaquin Valley of California. Grapevines adjusted to 45 clusters prior to bloom had one-third of their clusters removed at one of the following stages of fruit development: prebloom (PB), berry set (BS), berry set + 2 weeks (BS + 2), berry set + 4 weeks (BS + 4), and berry set + 6 weeks (BS + 6). A group of unthinned vines, carrying 45 clusters throughout the season, were included in the study. The leaf area:fruit weight ratios for vines thinned at BS and unthinned vines, respectively, were 11.9 and 10.2 cm² g^-1 in 1991 and 15.5 and 11.4 cm² g^-1 in 1992. Little difference in berry fresh or dry weight was observed among the treatments prior to fruit softening. After fruit softening, vines thinned between PB and BS + 4 generally exhibited greater berry fresh and dry weights than vines thinned at BS + 6 and unthinned vines. Berry diameter did not differ among the treatments at harvest in either season. Berry color was the compositional parameter most sensitive to date of cluster thinning. Vines thinned between PB and BS + 4 accumulated color more rapidly than vines thinned at BS + 6 and unthinned vines. Fruit soluble solids at harvest were greater for cluster thinned vines compared to unthinned vines. Total and cull yield were greatest for unthinned vines in both seasons. In 1991, vines thinned at BS + 6 had the lowest packable yields in the experiment. In 1992, the packable yields of vines thinned at BS + 6 and unthinned vines were similar and significantly lower than those of the remaining treatments. The results indicate that mid-season ripening Flame Seedless table grapes may be cluster-thinned between PB and BS + 4 with similar effects on fruit growth, fruit composition, and packable yield. Due to reduced packable yields, as well as variable effects on fruit composition, cluster thinning after berry softening (BS + 6) is not recommended.

Sucrose phosphate synthase and other sucrose metabolizing enzymes in fruits of various species

Recent reports have suggested that sucrose phosphate synthase (EC 2.4.1.14), a key enzyme in sucrose biosynthesis in photosynthetic “source” tissues, may also be important in some sucrose accumulating “sink” tissues. These experiments were conducted to determine if sucrose phosphate synthase is involved in sucrose accumulation in fruits of several species. Peach (Prunus persica NCT 516) and strawberry (Fragaria x ananassa cv. Chandler) fruits were harvested directly from the plant at various stages of fruit development. Kiwi (Actinidia chinensis), papaya (Carica papaya), pineapple (Ananas comosus) and mango (Mangifera indica) were sampled in postharvest storage over a period of several days. Carbohydrate concentrations and activities of sucrose phosphate synthase, sucrose synthase (EC 2.4.1.13), and acid and neutral invertases (EC 3.2.1.26) were measured. All fruits contained significant activities of sucrose phosphate synthase. Moreover, in fruits from all species except pineapple and papaya, there was an increase in sucrose phosphate synthase activity associated with the accumulation of sucrose in situ. The increase in sucrose concentration in peaches was also associated with an increase in sucrose synthase activity and, in strawberries, with increased activity of both sucrose synthase and neutral invertase. The hexose pools in all fruits were comprised of equimolar concentrations of fructose and glucose, except in the mango. In mango, the fructose to glucose ratio increased from 2 to 41 during ripening as sucrose concentration more than doubled. The results of this study indicate that activities of the sucrose metabolizing enzymes, including sucrose phosphate synthase, within the fruit itself, are important in determining the soluble sugar content of fruits of many species. This appears to be true for fruits which sweeten from a starch reserve and in fruits from sorbitol translocating species, raffinose saccharide translocating species, and sucrose translocating species.

Partitioning of 14C-photosynthate in developing kiwifruit

Kiwifruit ( Actinidia deliciosa [A. Chev.] C.F. Liang et A.R. Ferguson var. deliciosa cultivar ‘Hayward’) leaves were allowed to photosynthesise 14CO 2 and the fate of the photosynthate in different tissue zones of the fruit was studied at various stages of fruit development. Photosynthate moved into the fruit at all stages of fruit development examined (February, April, May). Proportionally more photosynthate was allocated to the core in May than in February. In May, a greater proportion of radioactive photosynthate was found at the stem end of the fruit than in the blossom end of the fruit. There was a diurnal pattern of incorporation of label into the insoluble residue and organic acid fractions in all tissues in February. Both the proportion and amount of radioactivity incorporated into the insoluble residue and organic acid fractions decreased as the fruit matured. The results support the concept that the core is metabolically more active than the inner cortex at late stages of fruit development, and indicate that the different concentrations of quinic and citric acids found in each tissue are not due to different rates of metabolism of photosynthate within the tissues. Evidence is given that the greater concentration of soluble solids occurring at the blossom end rather than the stem end of the fruit in April and May is not caused by incoming photosynthate.

Ethylene-Promoted Conversion of 1-Aminocyclopropane-1-Carboxylic Acid to Ethylene in Peel of Apple at Various Stages of Fruit Development

Internal ethylene concentration, ability to convert 1-amino-cyclopropane-1-carboxylic acid (ACC) to ethylene (ethylene-forming enzyme [EFE] activity) and ACC content in the peel of apples (Malus domestica Borkh., cv Golden Delicious) increased only slightly during fruit maturation on the tree. Treatment of immature apples with 100 microliters ethylene per liter for 24 hours increased EFE activity in the peel tissue, but did not induce an increase in ethylene production. This ability of apple peel tissue to respond to ethylene with elevated EFE activity increased exponentially during maturation on the tree. After harvest of mature preclimacteric apples previously treated with aminoethoxyvinyl-glycine, 0.05 microliter per liter ethylene did not immediately cause a rapid increase of development in EFE activity in peel tissue. However, 0.5 microliter per liter ethylene and higher concentrations did. The ethylene concentration for half-maximal promotion of EFE development was estimated to be approximately 0.9 microliter per liter. CO(2) partially inhibited the rapid increase of ethylene-promoted development of EFE activity. It is suggested that ethylene-promoted CO(2) production is involved in the regulation of autocatalytic ethylene production in apples.

Hydrocarbons from epicuticular waxes of Citrus peels

The hydrocarbon fraction of the epicuticular wax layer of peel from 5 cultivars of Citrus was monitored at various stages of fruit development. GLC

Determinação do grau de maturação do abacate (Persea americana Miller), através da utilização do pressômetro

Um experimento foi realizado com o objetivo de averiguar o valor do pressômetro (Fruit Pressure Testers) na determinação do grau de maturação do abacate. Foram estudados frutos de três regiões ecologicamente diferentes do Estado de São Paulo (Novo Horizonte, Limeira e Itapetininga). Em cada região, utilizou-se de três pomares e em cada pomar selecionou-se cinco árvores das cultivares 'Wagner', 'Prince' e 'Collinson', colhendo-se dois frutos de cada árvore, que no conjunto (10 frutos) formaram a amostra a ser analisada, para cada cultivar. Efetuou-se colheitas em épocas predeterminadas visando a análise das variações da dureza da polpa do fruto durante o seu desenvolvimento, desde a sua formação até a época de maturação. Utilizando-se do pressômetro, observou-se um aumento gradativo da dureza da polpa com o desenvolvimento do fruto, provavelmente devido a diminuição constante de umidade da polpa. Apesar de se constatar índices diferentes para os diversos estágios de desenvolvimento do fruto, essas diferenças não foram suficientemente amplas de modo a permitir um seguro critério de maturação para o abacate. Constatou-se não obstante, condições mais favoráveis para a utilização do pressômetro em frutos produzidos em regiões mais frias, onde se obtém índices mais amplos, nos diversos estágios de desenvolvimento do fruto. Foi constatado em todas as cultivares testadas, no estágio inicial do desenvolvimento do fruto, diferenças entre os índices obtidos nas três regiões estudadas, observando-se índices mais altos nas regiões mais quentes.

Biochemical aspects of the developing and ripening banana

The peel and pulp of the banana fruit and the pseudostem were examined for glutamate-oxaloacetate transaminase (GOT), glutamate-pyruvate transaminase (GPT) and aldolase activities and protein, phenolics, chlorophyll and starch. The peel-pulp ratio at various stages of fruit development on the plant and in detached fruits showing incipient ripening were used as an index of the physiological age of the fruit. The enzymes exhibited maximum activity at a stage corresponding to the initiation of the climacteric. GPT level at this stage was higher than that of GOT. An initial increase in the protein content was followed by a decline in both peel and pulp, the level reaching a minimum in climacteric fruits. Astringency, measured in terms of total phenolics, decreased with development; in mature fruits, peel contained 4–5 × as much phenolics as pulp. Chlorophyll in mature fruits was 10 × higher than in young fruits and decreased in ripe fruits. The onset of ripening was attended with a pronounced decrease in the starch. The various analyses were carried out also on the pseudostem removed from the plant soon after flower formation.

Diurnal Changes in Diameters of Fruits and Tree Stems of Montmorency Cherry

SummaryDiurnal expansion and contraction of fruits and tree stems of Montmorency cherry (Prunus cerasus L.) were studied during various stages of fruit development. Experiments were performed under conditions of frequent irrigation as well as during soil-drying cycles. Fruits in a mid stage of development often shrank during the morning and early afternoon and expanded, beginning in late afternoon and continuing into the night. Fruits in mid stages of development usually shrank more than stems. The time of beginning, amount, and duration of shrinkage varied with the stage of fruit development, soil moisture availability, weather, and degree of internal water stress in the tree. When soil moisture contents were high the amount, time, and ending of daily shrinkage were correlated with conditions affecting transpiration. During early development (stage I) fruits usually increased in diameter in spurts and did not shrink appreciably during the day, except under severe internal water stress. As fruits approached maturity (stage III) they showed a strong tendency for water uptake and limited water loss. In nearly mature fruits afternoon expansion tended to predominate even when the soil was dry. Maturing fruits could be made to shrink appreciably, however, by high internal water deficits.