Soluble Sugars and Sucrose-Metabolizing Enzymes Related to Cold Acclimation of Sweet Cherry Cultivars Grafted on Different Rootstocks

The bark tissues were collected from 4-year-old sweet cherry trees cvs. 0900 Ziraat and Lambert grafted on Gisela 5 and Mazzard rootstocks in cold-acclimated (CA) and nonacclimated (NA) stages. Bark tissues subjected to 4°C and −5°C injured to a limited extent in both stages. However, more than 50% injury occurred by temperatures equal to or colder than −15°C only in NA period. Total soluble sugar (TSS), reducing sugars, and sucrose contents were higher in CA than those in NA stages in all samples. The activities of acid invertase (EC 3.2.1.26) and sucrose synthase (SS) (EC 2.4.2.13) enzymes were higher in NA stage than those in CA stage. Considering the rootstocks, reducing sugars were higher in both cultivars grafted on Gisela 5 whereas sucrose contents were higher in both cultivars grafted on Mazzard. However, the enzyme activities of both cultivars were higher on Mazzard rootstock than on Gisela 5. In conclusion, cold hardiness of sweet cherry graft combinations was suggested by increasing their TSS, reducing sugars, and sucrose contents significantly in the CA stage. Moreover, acid invertase and SS are down regulated during cold acclimation. Indeed the results suggested that Mazzard is more cold-hardy rootstock than Gisela 5

Soluble sugars and sucrose-metabolizing enzymes related to cold acclimation of sweet cherry cultivars grafted on different rootstocks

The bark tissues were collected from 4-year-old sweet cherry trees cvs. 0900 Ziraat and Lambert grafted on Gisela 5 and Mazzard rootstocks in cold-acclimated (CA) and nonacclimated (NA) stages. Bark tissues subjected to 4 degrees C and -5 degrees C injured to a limited extent in both stages. However, more than 50% injury occurred by temperatures equal to or colder than -15 degrees C only in NA period. Total soluble sugar (TSS), reducing sugars, and sucrose contents were higher in CA than those in NA stages in all samples. The activities of acid invertase (EC 3.2.1.26) and sucrose synthase (SS) (EC 2.4.2.13) enzymes were higher in NA stage than those in CA stage. Considering the rootstocks, reducing sugars were higher in both cultivars grafted on Gisela 5 whereas sucrose contents were higher in both cultivars grafted on Mazzard. However, the enzyme activities of both cultivars were higher on Mazzard rootstock than on Gisela 5. In conclusion, cold hardiness of sweet cherry graft combinations was suggested by increasing their TSS, reducing sugars, and sucrose contents significantly in the CA stage. Moreover, acid invertase and SS are down regulated during cold acclimation. Indeed the results suggested that Mazzard is more cold-hardy rootstock than Gisela 5

Impact of heat stress on sucrose metabolism of watermelon

High temperatures (HT) are a significant threat for crop production, and strategies for maintaining high crop yields and quality under HT stress are crucial agricultural objectives. The changes in sugar metabolism during HT stress were examined in watermelon cv. Crimson Tide leaves. The leaves obtained from plants were subjected to 35, 40, 45, 50, 55 and 60°C. Heat-stress tolerance (HST; LT50), hydrogen peroxide (H2O2), sucrose (Suc), reducing sugars and starch contents and some sucrolytic enzyme activities in leaf samples held at each temperature for 30 minutes were determined. The HST and H2O2 content, rose with increasing temperatures, most noticeably between 50-55°C. As a result, the LT50 value was determined to be 53.84°C. The Suc content increased almost 2-fold between 50-55°C. The reducing sugars and starch content sharply decreased with HT up to 50°C comparing to the control, however both increased almost 2-fold between 50-55°C. The H2O2 may act as a signal molecule at 40-45°C and triggers sucrose metabolism. It was determined that alkaline-INV and SuSy activities were at the maximum level at 40°C. The increase in enzyme activities has been associated with increased energy needs under stress conditions. The findings revealed that sugar metabolism contributes significantly to HST

Heat-stress tolerance of some strawberry (fragaria × ananassa) cultivars

Physiological parameters were used to investigate genotypic variations in 15 strawberry cultivars ['Aromas', 'Camarosa', 'Carmine','Cal. Giant 3' (CG3), 'Cal. Giant 5' (CG5), 'Elsanta', 'Fern', 'Festival', 'Honeoye', 'Kabarla', 'Redlands Hope' (R.Hope), 'Ruby Gem', 'Selva', 'Sweet Charlie' and 'Whitney'] and their relationship to heat-stress tolerance (HST). Cold stored (frigo) strawberry seedlings were grown in pots for six weeks and then transferred to a growth chamber. The temperature in the growth chamber was increased stepwise from 35 to 40,45 and 50 degrees C to create a heat-stressed environment. Leaf relative water content (RWC), loss of turgidity and chlorophyll content were measured at each temperature. The 'Elsanta' and 'R.Hope' had the highest RWC, while the 'Festival' and 'CG3' had the lowest. However, 'Elsanta' and 'R.Hope' had the lowest loss of turgidity, while 'Festival' and 'CG3' had the highest. 'Elsanta' and 'R.Hope' showed the lowest chlorophyll content, and 'CG3' and 'Whitney' had the highest. To determine HST (LT50), leaf discs of each cultivar were exposed to 35, 40, 45, 50, 55 and 60 degrees C. A considerable decrease in the LT50 was observed with increasing temperature in all cultivars. The LT50 of the cultivars ranged from 51.8 to 52.9 degrees C. Based on the data collected, 'Elsanta', 'R. Hope' and 'Camarosa' were determined to be relatively heat-tolerant cultivars, while 'Whitney', 'Fern', 'Festival' and 'CG3' were heat-sensitive cultivars.Yaltır A.Ş. (Adana, Turkey

Changes of growth, amino acids, and ionic composition in strawberry plants under salt stress conditions

Seedlings of two strawberry cultivars 'Camarosa' and 'Chandler' were grown using perlite in a greenhouse for 20 days, and then plants were watered with nutrient solution containing 0, 8.5, 17.0, and 34.0mM sodium chloride (NaCl) for 6 months. Sodium chloride treatments generally reduced the leaf and root dry weight. Relative water content (RWC) of leaves was maintained despite the increased salt concentrations while loss of turgidity was increased by sodium chloride (NaCl) treatments in both cultivars. As the most variable amino acids, aspartic acid, glutamic acid, arginine, proline, serine, and alanine were determined under salt stress in plants. Sodium chloride treatments generally increased sodium (Na) and chloride (Cl) contents in all plant parts. The plants were able to maintain high potassium (K) levels in the aerial parts with the 8.5mM NaCl treatment. It can be concluded that 'Camarosa' has the ability to osmotic regulation. 'Chandler' also tolerates the salt injury at low salt concentrations

Researches on salt resistance physiology of strawberries grown in different media

Perlit ve perlitzeolit (1:1) ortamlarında değişik sürelerle (28, 69 ve 183 gün) farklı konsantrasyonlardaki (0, 500, 1000 ve 2000 mg/L NaCl) tuz uygulamalarının Camarosa, Tioga ve Chandler çilek çeşitlerinde bitki ve meyve özellikleri üzerindeki etkileri ile çeşitlerin tuza karşı reaksiyonları fizyolojik açıdan araştırılmıştır. Yapılan genel değerlendirmelere göre ortamlara, tuz konsantrasyonlarına ve süreleri ile çeşitlere bağlı olarak tuz uygulamalarının yaprak ve kök kuru ağırlığım azalttığı, bitkilerde farklı şiddetlerde zararlanmalara neden olduğu saptanmıştır. Aynı şekilde tuz uygulama süresinin artmasına bağlı olarak bitki canlılığının, meyve sayısının ve toplam verimin azaldığı belirlenmiştir. NaCl uygulamalarının yaprak oransal su kapsamım etkilemediği, turgor kaybım ve toplam klorofil miktarım arttırdığı saptanmıştır. Tuz uygulamaları sonucunda konsantrasyonlara, uygulama sürelerine ve çeşitlere bağlı olarak toplam protein ve toplam amino asit miktarlarında azalış veya artışlar olduğu gözlenmiştir. Uygulamalar sonunda en fazla değişime uğrayan amino asitlerin ise; prolin, aspartik asit, alanın ve glutamik asit olduğu belirlenmiştir. Bitkilerin toprak üstü organlarında, tuz uygulamaları sonucu Na, Cl, Fe ve Mn miktannm arttığı; K miktarının azaldığı; Ca, Mg, P, Zn ve Cu miktarının değişmediği belirlenmiştir. Toprak altı organlarda ise Na, Cl, Zn ve Cu miktarının arttığı; K ve Mg miktarının azaldığı; Ca, P, Fe ve Mn miktarının ise tuz uygulamalarından etkilenmediği gözlenmiştir. Ayrıca tuz uygulamalarının bitkilerin farklı organlarında K:Na oranını azalttığı, Na:Ca oranım ise arttırdığı tespit edilmiştir. Genel olarak tuz uygulamaları meyvede toplam şeker, titre edilebilir asit ve C vitamini miktarını arttırmış, meyve rengini iyileştirmiş; fakat meyve lezzeti artan tuz konsantrasyonu ile birlikte bozulmuştur. Camarosa ve Tioga çilek çeşitleri çoğu parametrede genellikle Chandler'a göre tuza daha dayanıklı bir karakter göstermiştir. Ayrıca perlitzeolit (1:1) ortamının, perlit ortamına oranla, bitkilerin tuza dayanıklılık performansları açısından daha olumlu sonuç verdiği gözlenmiştir.The effects of salt (NaCl) applications of various concentrations (0, 500, 1000 and 2000 mg/L) for various exposure times (28 days, 69 days, 183 days) on the plant and fruit characteristics of Camarosa, Tioga and Chandler strawberry varieties grown in perlite and perlite:zeolite (1:1) media and physiological responses of the varieties to the salt applications were investigated. According to the general evaluation, it was found that, salt applications reduced the leaf and root dry weight depending on the media, the salt concentrations and the exposure times, also it caused some damages in plants in various levels. Moreover plant viability, fruit number and total yield reduced, depending on the increase in salt exposure time. It was found that, NaCl applications did not effect the relative leaf water content, but increased the turgor losses. Total chlorophyll amount in the leafs was increased as a result of salt applications. At the end of the treatments, it was observed some increases or decreases in the total proteins and amino acids contents depending on the salt concentrations, exposure times and the varieties. As the most variable amino acids, proline, aspartic acid, alanine and glutamic acid were determined under salty conditions in the plants. With the effect of salt applications, the amount of Na, CI, Fe and Mn increased; while the amount of K decreased. The amount of Ca, Mg, P, Zn and Cu did not change in the above ground part of plants. In roots, it was observed that the amount of Na, CI, Zn and Cu increased; the amount of K and Mg decreased; Ca, P, Fe and Mn were not affected from the salt application. In addition, it was determined that the salt applications decreased the K:Na ratio and increased the Na:Ca ratio in various plant parts. In general, it was found that salt applications increased the content of total sugar, titratable acidity and vitamin C in fruit and improved fruit colour. However, the fruit taste became bad by the increased salt concentration The results indicated that, Camarosa and Tioga strawberry varieties had more resistant character than Chandler. In addition, regarding the salt resistant performance of plants, perlite:zeolite (1:1) medium had more effective results than perlite.YALTIR A.Ş

Changes of micronutrients, dry weight, and chlorophyll contents in strawberry plants under salt stress conditions

Various concentrations of NaCl (0, 500, 1000, and 2000 mg/L) were applied to plants of the "Camarosa" and "Tioga" strawberry varieties for 10 weeks. At the end of the experiment, it was determined that the leaf dry weight increased especially at 500 and 1000 mg/L NaCl treatments when compared to control treatment. However, salt applications did not change total chlorophyll content. With the salt applications, iron (Fe) and manganese (Mn) content increased, while copper (Cu) content did not change in the aerial part of plants in both varieties. On the other hand, zinc (Zn) content increased in the "Tioga" strawberry variety. In the root part of plants, Fe, Zn, Mn and contents did Dot change according to salt applications in both strawberry varieties. However, 2000 mg/L NaCl of salt applications increased Cu content in the "Camarosa" strawberry variety significantly