Transcriptomics Analysis and Candidate Genes Associated With Xinjiang Jujubes in Response to Alternaria Alternata Infection

BackgroundBlack spot disease, caused by Alternaria altrenata, is one of the most destructive diseases of jujube worldwide. To better understand the resistance mechanisms of jujube to A. altrenata infection to be able to improve disease control and resistance breeding. Two different cultivars, Zizyphus jujuba Mill. var. Jun jujube (susceptible) and Zizyphus jujuba Mill. var. Hui jujube (resistant), were tested. ResultsIn this study, we identified 2235 differentially expressed genes (DEGs) in the disease-resistant cultivar and 4958 in the susceptible cultivar. To better understand these DEGs, the datasets were analyzed using Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genome (KEGG) database. Most of them were associated with plant phytohormone synthesis and signal transduction, flavonoid synthesis, and glutathione metabolism. The expression of 6 DEGs associated with disease resistance were detected by real time-quantitative polymerase chain reaction (RT-qPCR), consistent with the results of Illumina transcriptome sequencing. Moreover, the expression level of the six DEGs differently in Jun jujube and Hui jujube, verified they are defense response factors. ConclusionsThe present study identified several candidate resistance genes and signal transduction pathways that may contribute to black spot disease resistance in jujube, which will assist the investigation of resistance mechanisms in the response of jujube to A. altrenata infection.

Substantiation of the adaptability of Zizyphus jujuba varieties to the climatic conditions of the Volgograd region

Актуальность обусловлена интродукцией субтропической плодовой культуры Zizyphus jujuba(унаби) в Волгоградскую область. Впервые в условиях Волгоградской области проанализирован и обобщен материал по биохимическим свойствам различных сортов плодов унаби. Цель исследований – изучение адаптивных реакций субтропических растений Zizyphus jujubа в северных точках возделывания на основе их биохимических и физиологических параметров. Объекты - растительные генотипы Z. jujuba: крупноплодные, среднеплодные и мелкоплодные. Опытные посадки с их участием возделываются на коллекционном участке ФНЦ агроэкологии РАН (Волгоград, Россия). Исследование адаптивных реакций на изменение условий среды базируется на фиксации экологических факторов и биоэкологии растительных особей на основе их физиологических и биохимических параметров в полевых и лабораторных условиях. В задачи исследований входило: выявление лимитирующих факторов, ограничивающих развитие; анализ критических периодов развития растений по изменению водного обмена и температурного режима; сравнительная оценка биохимических характеристик плодов в северной точке ареала культивирования с учетом адаптации к стресс-факторам (генотип-среда). Выявлено, что недостаток воды приводит к увеличению концентрации растворимых веществ. Обезвоживание приводит к нарушению целостности мембран и оказывает влияние на состав пигментного комплекса. Установлена вариабельность содержания аскорбиновой кислоты по годам: у крупноплодных и среднеплодных растений от 31,9 до 66,5 мг %. У мелкоплодных растений в условиях культивирования вариабельность по годам менее выражена. В засушливый период (общий запас влаги в почве до двух метров 130-141 мм) содержание аскорбиновой кислоты снижается. Мелкоплодные растения, проявляющие высокую степень адаптации, имеют большие показатели содержания аскорбиновой кислоты (до 740,3 мг %). Ограничивающими факторами являются повышения температур и снижение влажности воздуха в летний период при малом количестве осадков и запаса влаги в корнеобитаемом слое почвы. Продуктивность растений при стрессе сильно зависит от поддержания водного статуса растений. Любая оценка водного статуса должна учитывать реакцию растений на условия окружающей среды и характеристику этих условий The relevance is due to the introduction of the subtropical fruit culture Zizyphus jujuba (unabi) to the Volgograd region. For the first time in the conditions of the Volgograd region, the material on the biochemical properties of various varieties of una-bi fruits was analyzed and generalized. The aim of the research is to study the adaptive reactions of subtropical plants of Zizyphus jujuba in the northern points of cultivation based on their biochemical and physiological parameters. The objects are plant genotypes of Z. jujuba: large-fruited, medium-fruited and small-fruited. Experimental plantings with their participation are cultivated at the collection site of the Federal Research Center for Agroecology of the Russian Academy of Sciences (Volgograd, Russia). The study of adaptive reactions to changing environmental conditions is based on the fixation of environmental factors and bioecology of growing individuals based on their physiological and biochemical parameters in the field and laboratory conditions. The research objectives included: identification of limiting factors limiting development; analysis of critical periods of plant development by changes in water metabolism and temperature regime; comparative assessment of the biochemical characteristics of fruits in the northern point of the cultivation area, taking into account adaptation to stress factors (genotype-environment). It was revealed that the lack of water leads to an increase in the concentration of soluble substances. Dehydration leads to a violation of the integrity of the membranes and affects the composition of the pigment complex. The variability of ascorbic acid content by years was established: in large-fruited and medium-fruited plants from 31.9 to 66.5 mg %. In small-fruited plants under cultivation, the variability over the years is less pronounced. During the dry period (the total moisture reserve in the soil is up to two meters 130-141 mm), the content of ascorbic acid decreases. Small-fruited plants showing a high degree of adaptation have high rates of ascorbic acid content (up to 740.3 mg%). Limiting factors are temperature increases and a decrease in air humidity in summer with low rainfall and moisture reserves in the root layer of the soil.The productivity of plants under stress strongly depends on the maintenance of the water status of plants. Any assessment of the water status should take into account the reaction of plants to environmental conditions and the characteristics of these conditions

MORPHOLOGICAL AND CHEMICAL ANALYSIS OF ZIZYPHUS JUJUBA MILL. FRUITS FROM TIMIȘOARA BOTANICAL PARK

Zizyphus jujuba Mill. belongs to the Rhamnales order, Rhamnaceae family, Rhamnus genus. The genus includes about 40 species native to tropical and subtropical regions of both hemispheres, as well as the Mediterranean region. Species Zizyphus jujuba Mill. it is native to SW Asia, has ornamental features and is found spontaneously on the Danube coast. The first cultivated varieties were introduced at the Faculty of Horticulture in Bucharest in Shanxi Province, China in a joint research project in 1997. In our study, the fruits were harvested from two genotypes in the Botanical Park of Timisoara. For the harvested fruits were analyzed: fruit weight (g), seed weight (g), fruit length (mm), fruit width (mm) and chemical analyses were performed: soluble dry matter (%), C vitamin (mg 100 g-1), total potassium content (mg 100 g-1) and protein (%). In the analyzed fruits, the soluble dry matter varied between 28.3-29.81%, C vitamin between 247.97-288.17 mg 100g-1, proteins between 4.84-5.63% and potassium between 79.53 -79.63 mg 100 g-1.