Same Season and Carry-Over Effects of Source-Sink Adjustments on Grapevine Yields and Non-structural Carbohydrates

The grapevine (Vitis vinifera L.) is managed to balance the ratio of leaf area (source) to fruit mass (sink). Over cropping in the grapevine may reveal itself as spontaneous fruit abortion, delayed ripening, or as alternate bearing. The aim of this work was to study the same season and carry-over effects of manipulating source to sink ratios on grapevine phenology, leaf gas exchange, yield components, berry soluble solids accumulation, and reserve carbohydrate and soluble sugar concentration in roots. Cabernet Sauvignon grapevines were subjected to defoliation (33, 66, and 100% of the leaves retained) and fruit removal treatments (33, 66, and 100% of clusters retained) arranged in a factorial design. Results from two seasons of source-sink manipulations were substantially different. In both seasons defoliation treatments affected season-long net carbon assimilation (AN) and stomatal conductance (gs) where the less leaves were retained, the greater the AN and gs, and fruit removal had no impact on leaf gas exchange. In the first season, leaf area to fruit mass was hardly related to berry soluble solids and in the second season they were strongly correlated, suggesting a degree of acclimation. Defoliation treatments had great impacts on berry size, berries per cluster, and total soluble solids in both years. Fruit removal treatments only had effects on berry mass and berries per cluster in the first season, and only on berry soluble solids in the second. The predominant effect of defoliation (carbon starvation) cascaded onto reducing root starch content, root mass and delaying of veraison and leaf senescence, as well as harvest which was delayed up to 9 weeks with 33% of the leaves retained. In a third season, where grapevines grew without treatments, defoliation treatments had resultant carryover effects, including reduced leaf area, number of berries per cluster, clusters per vine, and yield, but not on leaf gas exchange dependent on previous seasons' severity of defoliation. Balancing source-to-sink ratio is crucial to obtain an adequate speed of ripening. However, this was the culmination of a more complex whole-plant regulation where the number of leaves (source strength) outweighed the effects of fruits (sink strength).

Fructan Structure and Metabolism in Overwintering Plants

In northern regions, annual and perennial overwintering plants such as wheat and temperate grasses accumulate fructan in vegetative tissues as an energy source. This is necessary for the survival of wintering tissues and degrading fructan for regeneration in spring. Other types of wintering plants, including chicory and asparagus, store fructan as a reserve carbohydrate in their roots during winter for shoot- and spear-sprouting in spring. In this review, fructan metabolism in plants during winter is discussed, with a focus on the fructan-degrading enzyme, fructan exohydrolase (FEH). Plant fructan synthase genes were isolated in the 2000s, and FEH genes have been isolated since the cloning of synthase genes. There are many types of FEH in plants with complex-structured fructan, and these FEHs control various kinds of fructan metabolism in growth and survival by different physiological responses. The results of recent studies on the fructan metabolism of plants in winter have shown that changes in fructan contents in wintering plants that are involved in freezing tolerance and snow mold resistance might be largely controlled by regulation of the expressions of genes for fructan synthesis, whereas fructan degradation by FEHs is related to constant energy consumption for survival during winter and rapid sugar supply for regeneration or sprouting of tissues in spring.

Quantificação de açúcares totais e auxina no desenvolvimento inicial de mini-toletes de cana-de-açúcar

Reserve carbohydrate and auxinspresent in the stalk are involved in the development of sugarcane plant. Thus, this study aimed to quantify total sugarsand auxin of type indoleacetic acid (IAA) content in the initial development of stalks and sugarcane buds, as a function of diameter and position in the stalk. The experiment was conducted in a 3x3 factorial scheme (diameter x stalk section), with four replicates. Eleven-month-old plants stalks were classified into three diameters (fine < 2 cm; medium 2-3 cm; thick > 3 cm) and divided into three sections (apex, middle and base). Data were submitted to analysis of variance, and when significant the means were compared by the Tukey (p≤0.05). The diameter factor resulted in greater interference in the content of the biochemical variables evaluated (sugars and auxin), in comparation to stalk section. Biometric variables (length and dry mass of shoot and roots, budding and budding speed index), in general, were mostly affected by stalk section factor. The diameter factor interfered in the content of endogenous auxin in the stalk and buds. Root growth was related to endogenous auxin concentration and the highest sprouting percentage was obtained from the apical section of the talk due to the availability of reducing sugars content.The use of mini-stalks for the propagation of sugarcane proved feasible.Keyword:apical dominance;plant hormone; propagation;Saccharum spp.

Evolutionary Engineering of an Iron-Resistant Saccharomyces cerevisiae Mutant and Its Physiological and Molecular Characterization

Iron plays an essential role in all organisms and is involved in the structure of many biomolecules. It also regulates the Fenton reaction where highly reactive hydroxyl radicals occur. Iron is also important for microbial biodiversity, health and nutrition. Excessive iron levels can cause oxidative damage in cells. Saccharomyces cerevisiae evolved mechanisms to regulate its iron levels. To study the iron stress resistance in S. cerevisiae, evolutionary engineering was employed. The evolved iron stress-resistant mutant “M8FE” was analysed physiologically, transcriptomically and by whole genome re-sequencing. M8FE showed cross-resistance to other transition metals: cobalt, chromium and nickel and seemed to cope with the iron stress by both avoidance and sequestration strategies. PHO84, encoding the high-affinity phosphate transporter, was the most down-regulated gene in the mutant, and may be crucial in iron-resistance. M8FE had upregulated many oxidative stress response, reserve carbohydrate metabolism and mitophagy genes, while ribosome biogenesis genes were downregulated. As a possible result of the induced oxidative stress response genes, lower intracellular oxidation levels were observed. M8FE also had high trehalose and glycerol production levels. Genome re-sequencing analyses revealed several mutations associated with diverse cellular and metabolic processes, like cell division, phosphate-mediated signalling, cell wall integrity and multidrug transporters.

ABOUT THE UNIVERSAL TECHNOLOGY OF PROCESSING JERUSALEM ARTICHOKE AND CHICORY FOR INULIN

The purpose of this work is development of the universal technology of processing of a girasol and chicory for an inulin according to requirements to quality of a feed stock. An inulin — the reserve carbohydrate widespread in flora. There is the most of inulin quantity in chicory, a girasol, much less is in onions, garlic, inula, yakena, etc. The inulin is widely applied as a low-calorie product in a dietary and diabetic food, just also as a jelly former in food. In the All-Russian Research Institute of Starch Products there are conducted researches on development of the universal technology for an inulin from inulin-containing raw materials. The technological assessment of a girasol and chicory from various regions of the Russian Federation is carried out, their physical and chemical indexes are defined. Requirements to processing behavior of raw materials are developed for inulin processing. By results of researches initial requirements to inulin-containing raw materials are defined: a mass fraction of dry solids is not less than 25 %, an inulin is not less than 16 %; mono — and disaccharides are 2 %. Diffusion from freshly harvested and dry chicory shavings and a girasol is studied, optimal established conditions are temperature 80–85ºC; the hydromodule for dry shaving — 1:7; for crude one — 1:2. It is developed the purification mode for extract and girasol and chicory syrups with use of various adsorbents such as the fissile coal, ion-exchange resins. The established high extent of extract and syrup purification is resulted in considerable decrease in a chromacity, mass fraction of a protein, ashes, etc. For researches as control specimens there was used an inulin of the foreign companies. Significance of the work is the creation of domestic technology of an inulin as prebiotic component for a treatmentand-prophylactic nutrition of the population and ensuring its import substitution.

Разработка и тестирование универсальных праймеров для ПЦР-амплификации генов-ортологов β-фруктофуранозидазы (Pain-1) у видов и сортов картофеля

Работа посвящена разработке и тестированию универсальных праймеров для ПЦР-амплификации полноразмерных генов-ортологов β-фруктофуранозидазы (кислой вакуолярной инвертазы) у видов и сортов картофеля (Solanum tuberosum). Крахмал – основной источник энергии и резервный углевод, накапливающийся в амилопластах клубней. Образовавшаяся в результате фотосинтеза молекула глюкозы при реакции с фруктозой образует сахарозу – основную транспортную форму углеводов в растении. В клубни сахароза доставляется по флоэме (апопластный путь), где в межклеточном пространстве расщепляется до глюкозы и фруктозы, которые затем проникают в клетки паренхимы. Глюкоза служит в дальнейшем субстратом для синтеза крахмала в амилопластах. Однако при воздействии пониженных температур крахмал в клубнях картофеля разрушается до редуцирующих сахаров. Параллельно этому процессу идет ресинтез сахарозы до глюкозы и фруктозы за счет фермента кислой вакуолярной инвертазы (β-фруктофуранозидазы), кодируемой геном Pain-1. В совокупности эти процессы приводят к избыточному накоплению моносахаров в клубнях картофеля, так называемому холодовому осахариванию (cold-induced sweetening). При этом создаются условия для интенсивного образования меланоидинов, вызывающих потемнение мякоти картофеля, что значительно ухудшает товарное качество продукта. Таким образом, изучение гена Pain-1, кодирующего вакуолярную инвертазу, а именно, его идентификация и анализ структуры – важная задача, необходимая для поиска доноров, устойчивых к холодовому осахариванию. Первоочередная задача для этого – разработка и тестирование праймерных комбинаций, позволяющих амплифицировать полноразмерный ген у диких видов картофеля, а также сортов и линий культивируемого картофеля (S. tuberosum). В данной работе приведены результаты разработки и тестирования универсальных праймеров, с помощью которых можно амплифицировать как полноразмерные гены-ортологи, так и фрагменты гена Pain-1, а также подобраны оптимальные условия для проведения ПЦР реакции. Было разработано 6 праймерных комбинаций (PainF – PainR, PainF – Pain1exR, Pain1exF – Pain3exR, Pain2inF – Pain2inR, Pain3exF – Pain5exR, Pain5exF – PainR), среди которых комбинация PainF – PainR позволяла амплифицировать полноразмерный ген, остальные – внутренние и будут использованы в дальнейшем при секвенировании фрагментов исследуемого гена. Эти праймеры были успешно протестированы на 15 образцах, включающих представителей пяти дикорастущих видов картофеля (S. gourlay, S. chacoense, S. pinnatissectum, S. stoloniferum, S. vernei) и десяти сортов российской и зарубежной селекции (Гала, Ласунок, Ред Скарлетт, Рассет Бербанк, Мирас, Башкирский, Жуковский ранний, Матушка, Елизавета, Сударыня).The purpose of research is design and testing of universal primers for PCR amplification of full-length-fructofuranozidase orthologs genes (acid vacuolar invertase) in wild species and potato (Solanum tuberosum) varieties. Starch is the main source of energy and a reserve carbohydrate, that accumulates in tubers amyloplasts. Glucose molecule, produced by photosynthesis, reacts with fructose and forms sucrose, which is the main transport type of carbohydrates in the plant. In the tuber, sucrose is delivered via phloem (apoplast), where it splits into glucose and fructose, which then go to the parenchyma cells. Glucose is a further substrate for the starch synthesis in amyloplasts. However, low temperatures influence on potato tubers leads to starch break down to reducing sugars. In parallel to this process there is happens resynthesis of sucrose to glucose and fructose by acid vacuolar invertase enzyme (β-fructofuranosidase) encoded by Pain-1 gene. Together, these processes lead to an excessive accumulation of monosaccharides in potato tubers. This process also called as cold-induced sweetening. It creates conditions for the intensive formation of melanoidins, which cause a potato tubers darkening, which considerably impairs the commercial quality of the product. Thus, the study Pain-1 gene that encodes the vacuolar invertase (its identification and structure analysis) is an important task required for the search of donors resistant to cold-induced sweetening. The primary task for this is the design and testing of primer combinations that allow to amplify the full-length gene in wild potato species, varieties and lines of cultivated potato. In this work, we develop and test universal primers, that can amplify both full-length orthologs and fragments of the Pain-1 gene, and also select the optimal conditions for carrying out the PCR reaction. Summary. The purpose of research is design and testing of universal primers for PCR amplification of full-length-fructofuranozidase orthologs genes (acid vacuolar invertase) in wild species and potato (Solanum tuberosum) varieties. Starch is the main source of energy and a reserve carbohydrate, that accumulates in tubers amyloplasts. Glucose molecule, produced by photosynthesis, reacts with fructose and forms sucrose, which is the main transport type of carbohydrates in the plant. In the tuber, sucrose is delivered via phloem (apoplast), where it splits into glucose and fructose, which then go to the parenchyma cells. Glucose is a further substrate for the starch synthesis in amyloplasts. However, low temperatures influence on potato tubers leads to starch break down to reducing sugars. In parallel to this process there is happens resynthesis of sucrose to glucose and fructose by acid vacuolar invertase enzyme (β-fructofuranosidase) encoded by Pain-1 gene. Together, these processes lead to an excessive accumulation of monosaccharides in potato tubers. This process also called as cold-induced sweetening. It creates conditions for the intensive formation of melanoidins, which cause a potato tubers darkening, which considerably impairs the commercial quality of the product. Thus, the study Pain-1 gene that encodes the vacuolar invertase (its identification and structure analysis) is an important task required for the search of donors resistant to cold-induced sweetening. The primary task for this is the design and testing of primer combinations that allow to amplify the full-length gene in wild potato species, varieties and lines of cultivated potato. In this work, we develop and test universal primers, that can amplify both full-length orthologs and fragments of the Pain-1 gene, and also select the optimal conditions for carrying out the PCR reaction. In total 6 primer combinations were designed (PainF - PainR, PainF - Pain1exR, Pain1exF - Pain3exR, Pain2inF - Pain2inR, Pain3exF - Pain5exR, Pain5exF - PainR), where PainF - PainR primer combination allowed to amplify a full-sized gene, the rest are internal and will be used in the further fragments sequencing of the β-fructofuranosidase gene. These primers were successfully tested on 15 samples, including five wild species of potato (S. gourlay, S. chacoense, S. pinnatissectum, S. stoloniferum, S. vernei) and ten varieties of Russian and foreign breeding (Gala, Lasunok, Red Scarlet , Rasset Burbank, Miras, Bashkirsky, Zhukovsky ranniy, Matushka, Elizaveta, Sudaryna).