scholarly journals Accumulation of Abnormal Amyloplasts in Pulp Cells Induces Bitter Pit in Malus domestica

2021 ◽  
Vol 12 ◽  
Author(s):  
Lina Qiu ◽  
Shanshan Hu ◽  
Yongzhang Wang ◽  
Haiyong Qu

Apple bitter pit primarily occurs during fruit ripening and storage; however, its formation mechanism remains unclear. Although it is considered that Ca2+ deficiency causes metabolic disorders in apples, there have been few studies on the mechanism of the bitter pit from the perspective of cell structure. At the fruit ripening stage, the fruit with a bitter pit on the tree was taken as the research material. In this study, the microscopic observation revealed numerous amyloplasts in the pulp cells of apples affected with bitter pit, but not in the healthy pulp. Furthermore, the results of fluorescence staining and transmission electron microscopy (TEM) revealed that the bitter pit pulp cells undergo programmed cell death (PCD), their nuclear chromosomes condense, and amyloplast forms autophagy. The cytoplasmic Ca2+ concentration in the healthy fruits was lowest near the peduncle, followed by that in the calyx, whereas it was highest at the equator. In contrast, the cytoplasmic Ca2+ concentration in apple fruits showing bitter pit disorder was lowest near the peduncle and highest in the calyx. Moreover, the cytosolic Ca2+ concentration in the flesh cells of apples with the bitter pit was much lower than that in the healthy apple flesh cells; however, the concentration of Ca2+ in the vacuoles of fruits with the bitter pit was higher than that in the vacuoles of healthy fruits. In summary, bitter pit pulp cells contain a large number of amyloplasts, which disrupts the distribution of Ca2+ in the pulp cells and causes PCD. These two processes lead to an imbalance in cell metabolism and induce the formation of a bitter pit.

1973 ◽  
Vol 24 (3) ◽  
pp. 363 ◽  
Author(s):  
TL Lewis ◽  
D Martin

When 45Ca-labelled calcium chloride solution was applied to the skin of young developing Merton apple fruits, activity in the cortex at maturity was highest in the calyx end region where bitter pit lesions most commonly develop. Fruit age at time of application affected the amount of labelled calcium absorbed but not its longitudinal distribution. Following branch injection of labelled calcium chloride solution 8 weeks before harvest, activity in mature fruits was found mostly in the stem end. Leaves and buds accounted for 95% of the recovered activity, and the fruits for 5%, of which about one-quarter was in the calyx half. The same distribution pattern was found following injection of labelled calcium chloride solution into the fruit stem. The concentration of naturally occurring calcium in the cortex of the mature fruit declined steadily from stem end to calyx end. On the other hand, the magnesium concentration was lowest near the stem end and highest at the calyx end. The potassium concentration remained fairly constant along most of the length of the fruit, with a small increase at each end. The findings are discussed with regard to the longitudinal gradient in bitter pit susceptibility within apple fruits, and to the relative effectiveness of tree sprays of calcium, as compared with soil applications, in the control of the disorder. Results suggest that calcium does not have a trace element role in the control of bitter pit.


2021 ◽  
Vol 7 (3) ◽  
pp. 42-51
Author(s):  
Thi Ly Nguyen ◽  
Thi The Doan ◽  
Phuong Anh Pham Nguyen ◽  
Van Chung Cao ◽  
Anh Tuyet Dinh Thi ◽  
...  

Lasiodiplodia theobromae causes decay of star apple fruits (Chrysophyllum cainino) during harvest, transport and storage. If the irradiation dose is higher than 800 Gy, this mold will be controlled. However, the quality of star apple was significantly changed when they were irradiated at the dose higher than 0.6 kGy by electron beam (EB). To keep irradiation dose under 0.6kGy, the synergic effect of the combined treatment of EB irradiation and sodium dichloroisocyanurate (NaDCC) was investigated. In this study, star apples were pretreated with NaDCC concentrations in range of 10 -70 ppm in order to decrease the growth of mold and extend the shelf-life of treated star apples. The results showed that pretreatment with 20 ppm NaDCC had also kept the color and reduced disease of stored star apple. Dipping star apples into 20 ppm NaDCC solution before irradiating at 400 Gy and 600 Gy could be chosen as the best way to inhibit the development of Lasiodiplodia theobromae and extend the shelf life of star apple in the trading condition (7 days, 9oC).


2001 ◽  
Vol 91 (2) ◽  
pp. 165-172 ◽  
Author(s):  
Ki Woo Kim ◽  
Eun Woo Park ◽  
Young Ho Kim ◽  
Kyung-Ku Ahn ◽  
Pan Gi Kim ◽  
...  

Apple fruit tissues infected with Botryosphaeria dothidea were examined by transmission electron microscopy using susceptible cv. Fuji and resistant cv. Jonathan. Immature (green) and mature (red) fruits of cv. Fuji with restricted or expanding lesions were also examined to reveal subcellular characteristics related with latent and restricted disease development. In infected susceptible mature fruits, cytoplasmic degeneration and organelle disruption commonly occurred, accompanying cell wall dissolution around invading hyphae. Cell wall dissolution around invading hyphae in subepidermis was rare in immature, red halo-symptomed cv. Fuji and resistant cv. Jonathan fruits. In infected immature fruits of cv. Fuji, presumably at the latent state of disease development, cellular degeneration was less severe, and invading hyphae contained prominent microbody-lipid globule complexes or the deposition of thin electron-dense outer layer around cell wall of intercellular hyphae. Both mature fruits with red halos and resistant apple fruits formed cell wall protuberances at the outside of cell walls. In addition, electron-dense extramural layers were formed in the resistant apple fruits. Aberrant hyphal structures such as intrahyphal hyphae were found only in resistant fruit tissues, indicating the physiologically altered fungal growth. These ultrastructural changes of host tissues and fungal hyphae may reflect the pathogenesis of apple white rot under varying conditions of apple fruits.


Author(s):  
Г.А. КУПИН ◽  
Т.В. ПЕРШАКОВА ◽  
А.В. СВЕРДЛИЧЕНКО ◽  
С.М. ГОРЛОВ

Проблема обеспечения высокого качества продукции для оптимизации затрат на ее производство и хранение актуальна для производителей и переработчиков плодовых культур. Исследовано влияние обработки плодов яблок препаратами на основе 1-метилциклопропена на изменение органолептических и биохимических показателей продукции при хранении. Объектом исследования были яблоки сорта Айдаред, выращенные на территории Краснодарского края, урожая 2020 года. При подготовке к исследованию часть яблоневых насаждений в период созревания плодов обрабатывали препаратом «Румянец» на основе 1-метилциклопропена в течение 28 дней с интервалом между обработками в 7 дней. После съема часть плодов с обработанных и необработанных деревьев перед закладкой на хранение была однократно обработана 1-метилциклопропеном с концентрацией активного вещества 1,4%. Для закладки на хранение были составлены 4 образца: образец 1 – необработанные плоды яблок (контроль); 2 – яблоки, обработанные препаратом «Румянец» в период созревания; 3 – яблоки, обработанные 1-метилциклопропеном перед закладкой на хранение; 4 – яблоки, обработанные препаратом «Румянец» в период созревания и 1-метилциклопропеном при закладке на хранение. Образцы яблок хранили при температуре (2 ± 1)°С и относительной влажности воздуха 85% в течение 30 сут. Установлено, что наивысшую оценку по значимым органолептическим показателям – площадь окрашенной поверхности, основная и покровная окраска кожицы, вкус и запах получил образец яблок 2. Его биохимические показатели на момент окончания срока хранения были выше по сравнению с аналогичными показателями контрольного образца. Содержание витамина С в плодах на момент окончания хранения снизилось: в контрольном образце на 7,3%, в образце яблок, обработанных в период созревания препаратом на основе 1-метилциклопропена, – на 3,6%. Дополнительная обработка яблок препаратом 1-метилциклопропена при закладке на хранение способствовала снижению органолептических показателей качества яблок (образцы 3 и 4). The problem of ensuring high quality products to optimize the cost of its production and storage is relevant for producers and processors of fruit crops. The effect of processing apple fruits with preparations based on 1-methylcyclopropene on the changes in the organoleptic and biochemical parameters of the products during storage was studied. The object of the study was apples of the Aydared variety grown on the territory of the Krasnodar region, the harvest of 2020. In preparation for the study, a part of apple plantations during the fruit ripening period was treated with the preparation «Rumyanets» based on 1-methylcyclopropene for 28 days with an interval between treatments of 7 days. After fruit picking, part of the fruits from the treated and untreated trees were treated once with 1-methylcyclopropene with a concentration of the active substance of 1.4% before being stored. 4 samples were prepared for storage: sample 1 – unprocessed apple fruits (control); 2 – apples treated with the preparation «Rumyants» during the ripening period; 3 – apples treated with 1-methylcyclopropene before storage; 4 – apples treated with the preparation «Rumyants» during the ripening period and 1-methylcyclopropene before storage. Apple samples were stored at a temperature of (2 ± 1)°C and relative humidity of 85% for 30 days. It was found that the highest score for significant organoleptic parameters – the area of the painted surface, the main and cover color of the skin, taste and smell had the sample of apples 2. Its biochemical parameters at the end of the storage period were higher than those of the control sample. The content of vitamin C in fruits at the end of storage decreased: in the control sample by 7,3%, in the sample of apples treated during maturation with a preparation based on 1-methylcyclopropene – by 3,6%. Additional treatment of apples with 1-methylcyclopropene preparation before storage contributed to a decrease in the organoleptic quality indicators of apples (samples 3 and 4).


Molecules ◽  
2020 ◽  
Vol 25 (20) ◽  
pp. 4622
Author(s):  
Piotr Kowalik ◽  
Tomasz Lipa ◽  
Zenia Michałojć ◽  
Mirosława Chwil

Calcium is one of the most poorly reutilized nutrients. Its deficiencies cause various physiological disturbances and, consequently, reduce the quantity and quality of yields. Reduced content of Ca2+ ions in cells leads to development of, e.g., bitter pit in apples. Efficient and instantaneous mitigation of Ca2+ deficiencies is provided by foliar feeding. There are no detailed data on the effect of foliar feeding with various calcium forms on the cell structure or on the microanalysis and mapping of this element in apple fruit cells. Therefore, we carried out comparative studies of the ultrastructure of epidermis and hypodermis cells, to assess the content and distribution of calcium in the cell wall, cytoplasmic membrane, cytoplasm, and precipitates of Malus domestica Borkh. ‘Szampion’ fruit exposed to four Ca treatments, including the control with no additional Ca supplementation (I) and foliar applications of Ca(NO3)2 (II), CaCl2 (III), and Ca chelated with EDTA (IV). Light and transmission electron microscopy and an X-ray microanalyzer were used and showed a beneficial effect of calcium preparations on the ultrastructure of fruit epidermis and hypodermis cells, manifested in the presence of a normally developed cell wall with a regular middle lamella, preserved continuity of cytoplasmic membranes, and stabilized cell structure. In the selected elements of apical epidermis cells, the highest level of Ca2+ ions was detected in the middle lamella, cell wall, plasmalemma, and cytoplasm. The highest increase in the Ca2+ content in these cell constituents was recorded in treatment IV, whereas the lowest value of the parameters was noted in variant III.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Guiyun Yi ◽  
Baolin Xing ◽  
Jianbo Jia ◽  
Liwei Zhao ◽  
Yuanfeng Wu ◽  
...  

Macroporous TiO2photocatalyst was synthesized by a facile nanocasting method using polystyrene (PS) spherical particles as the hard template. The synthesized photocatalyst was characterized by transmission electron microscope (TEM), scanning electron microscopy (SEM), thermogravimetry-differential thermogravimetry (TG-DTG), X-ray diffraction (XRD), and N2-sorption. TEM, SEM, and XRD characterizations confirmed that the macroporous TiO2photocatalyst is composed of anatase phase. The high specific surface area of 87.85 m2/g can be achieved according to the N2-sorption analysis. Rhodamine B (RhB) was chosen as probe molecule to evaluate the photocatalytic activity of the TiO2catalysts. Compared with the TiO2materials synthesized in the absence of PS spherical template, the macroporous TiO2photocatalyst sintered at 500°C exhibits much higher activity on the degradation of RhB under the UV irradiation, which can be assigned to the well-structured macroporosity. The macroporous TiO2material presents great potential in the fields of environmental remediation and energy conversion and storage.


IAWA Journal ◽  
2008 ◽  
Vol 29 (1) ◽  
pp. 55-68 ◽  
Author(s):  
Katarina Čufar ◽  
Jožica Gričar ◽  
Martin Zupančič ◽  
Gerald Koch ◽  
Uwe Schmitt

Evaluating the state of deterioration of water-logged archaeological wood is necessary in order to select treatments for its conservation and storage, particularly in the case of valuable archaeological artefacts. For this purpose archaeological wood of ash (Fraxinus sp.) and oak (Quercus sp.) buried in water-logged conditions at prehistoric settlements on the Ljubljansko barje (Ljubljana moor), Slovenia, aged approx. 5,200 and 4,500 years, was investigated by means of light microscopy (LM), transmission electron microscopy (TEM) and cellular UV-microspectrophotometry (UMSP). LM and TEM revealed that the ash wood aged 5,200 years was the least preserved. The secondary walls of fibres, vessels and parenchyma cells were considerably thinner than in normal wood, indicating distinct degradation. TEM and UMSP additionally revealed strong delignification of the remaining parts of the secondary walls of all cell types. The compound middle lamellae appeared structurally intact, but had lower UV-absorbance than normal wood of the same species. The cell corners were topochemically unchanged, as shown by high analogue UV-absorbance. The UV-absorbance maxima at a wavelength of 278 nm corresponded to those of hardwood lignins. The oak heartwood was generally better preserved than the ash wood. Within each species, the 4,500- year-old samples generally appeared better preserved than those 5,200 years old.


2018 ◽  
Vol 98 (14) ◽  
pp. 5435-5443
Author(s):  
Xian-Mei Yu ◽  
Jin-Zheng Wang ◽  
Pei-Xian Nie ◽  
Xiao-Min Xue ◽  
Gui-Ping Wang ◽  
...  

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