A Model for Selecting Kiwifruit () Germplasm Resources with Excellent Fruit Quality.

The evaluation of quality traits is an important procedure for kiwifruit breeding and comprehensive utilization. The present study aimed to establish a comprehensive system to assess germplasms by analyzing 22 quality traits on kiwifruit samples collected from a wild population of 236 plants grown in the Jiangxi Province, China. Variability, correlation, principal components, and cluster analyses were carried out using the data collected from fruit quality evaluations.

Kiwifruit Gene Negatively Regulates the Accumulation of Ascorbic Acid in Fruit of Transgenic Tomato Plants.

Ascorbic acid is a potent antioxidant and a crucial nutrient for plants and animals. The accumulation of ascorbic acid in plants is controlled by its biosynthesis, recycling, and degradation. Monodehydroascorbate reductase is deeply involved in the ascorbic acid cycle; however, the mechanism of genes in regulating kiwifruit ascorbic acid accumulation remains unclear.

MdNAC104 positively regulates apple cold tolerance via CBF-dependent and CBF-independent pathways.

Low temperature is the main environmental factor affecting the yield, quality and geographical distribution of crops, which significantly restricts development of the fruit industry. The NAC (NAM, ATAF1/2 and CUC2) transcription factor (TF) family is involved in regulating plant cold tolerance, but the mechanisms underlying these regulatory processes remain unclear. Here, the NAC TF MdNAC104 played a positive role in modulating apple cold tolerance.

Analysis of organic acid metabolism reveals citric acid and malic acid play major roles in determining acid quality during the development of kiwifruit (Actinidia eriantha).

Background: Actinidia eriantha is one of the most important kiwifruit species in Actinidia. The relative high accumulation of organic acids in fruit of A. eriantha is an unfavorable factor for organoleptic quality.

Prolonged On-Vine vs. Cold of : Differences in Fruit Quality and Aroma Substances during Soft Ripening Stage.

In order to find an efficient, economical and feasible method for soft ripening storage of kiwifruit, two softening methods (on-vine, cold) were utilized for the 'Ganlv-2' kiwifruit () cultivar. A comprehensive evaluation was conducted on the quality changes in 'Ganlv-2' under different methods after fruit ripening by principal component analysis and mathematical modeling. Compared to kiwifruit under cold softening, kiwifruit treated with on-vine soft ripening had slightly greater sugar-acid ratios and flesh firmness and higher contents of dry matter, soluble solids, and soluble sugar.

Genome-wide identification and expression profiling analysis of sucrose synthase (SUS) and sucrose phosphate synthase (SPS) genes family in Actinidia chinensis and A. eriantha.

Sucrose synthase (SUS) is a common sugar-base transfer enzyme in plants, and sucrose phosphate synthase (SPS) is one of the major enzymes in higher plants that regulates sucrose synthesis. However, information of the SPS and SUS gene families in Actinidia, as well as their evolutionary and functional properties, is limited. According to the SPS and SUS proteins conserved domain of Arabidopsis thaliana, we found 6 SPS genes and 6 SUS genes from A.

Genome-wide identification and characterization of the TIFY gene family in kiwifruit.

Background: The TIFY gene family is a group of plant-specific transcription factors involved in regulation of plant growth and development and a variety of stress responses. However, the TIFY family has not yet been well characterized in kiwifruit, a popular fruit with important nutritional and economic value.

Results: A total of 27 and 21 TIFY genes were identified in the genomes of Actinidia eriantha and A.

Metabolome and Transcriptome Reveal Novel Formation Mechanism of Early Mature Trait in Kiwifruit ().

Kiwifruit () is a peculiar berry resource in China, and the maturation period is generally late. Fortunately, we found an early mature germplasm. In order to explore the formation mechanism of its early mature trait, we determined the main carbohydrate and endogenous hormone content of the fruit, and used off-target metabolomics and transcriptomics to identify key regulatory metabolites and genes.

Genome-Wide Association Studies Provide Insights into the Genetic Determination of Flower and Leaf Traits of .

Kiwifruit () is a dioecious vine, and the pollen of its male cultivars has a direct effect on the quality of its fruits. In this study, to facilitate molecular breeding and gene identification, we performed genome-wide association studies (GWAS) on 11 traits of flower and leaf. A total of 946,337 highly consistent SNP markers were obtained in the whole genome.

Genome-wide identification and comprehensive analysis of NAC family genes involved in fruit development in kiwifruit (Actinidia).

Background: NAC transcription factors (TFs) are plant-specific proteins encoded by a large gene family. They play important roles in diverse biological processes, such as plant growth and development, leaf senescence, and responses to biotic or abiotic stresses. Functions of a number of NAC TFs have been identified mainly in model plants.

Three metabolic pathways are responsible for the accumulation and maintenance of high AsA content in kiwifruit (Actinidia eriantha).

Background: Actinidia eriantha is a precious material to study the metabolism and regulation of ascorbic acid (AsA) because of its high AsA content. Although the pathway of AsA biosynthesis in kiwifruit has been identified, the mechanism of AsA metabolism and regulation is still unclear. The purpose of this experiment is to reveal the AsA metabolic characteristics of A.

Differences of sucrose accumulation concentration and related genes expression between two sucrose accumulation types of Actinidia eriantha.

According to the investigation of wild Actinidia eriantha in Jiangxi province of China, we found that soluble solids content of fruit was lower than edible standard (14%). However, we found a high-sugar type A. eriantha line (code was 'MM24', test material) during investigative process at Nancheng county (E 116° 48', N 26° 23', 845 m).

Identification and expression profiling analysis of ascorbate peroxidase gene family in Actinidia chinensis (Hongyang).

Ascorbate peroxidase (APX) is one of the important antioxidant enzymes in the active oxygen metabolism pathway of plants and animals, especially it is the key enzyme to clear HO in chloroplast and the main enzyme of vitamin C metabolism. However, knowledge about APX gene family members and their evolutionary and functional characteristics in kiwifruit is limited. In this study, we identified 13 members of the APX gene family in the kiwifruit (cultivar: Hongyang) genome according the APX proteins conserved domain of Arabidopsis thaliana.

Characterization of Organic Acid Metabolism and Expression of Related Genes During Fruit Development of 'Ganmi 6'.

Studies on organic acid metabolism have been mainly concentrated on the fruit, whereas, few have focused on the mechanism of high organic acids content in the fruit of . Fruits of 'Ganmi 6' harvested at eleven developmental periods were used as materials. The components and content of organic acids were determined by high-performance liquid chromatography (HPLC) system, the activities of the related enzyme were detected, and gene expression levels were measured by quantitative real-time PCR (qRT-PCR).

An apple (Malus domestica) NAC transcription factor enhances drought tolerance in transgenic apple plants.

Plant NAC proteins constitute one of the largest transcription factor families. They play pivotal functions during responses to various abiotic stresses. However, knowledge on roles of NAC proteins in abiotic stress tolerance as well as corresponding mechanisms has not been fully studied in perennial woody plants, including domesticated apple (Malus domestica).

Overexpression of a Novel Apple NAC Transcription Factor Gene, MdNAC1, Confers the Dwarf Phenotype in Transgenic Apple (Malus domestica).

Plant height is an important trait for fruit trees. The dwarf characteristic is commonly associated with highly efficient fruit production, a major objective when breeding for apple (). We studied the function of , a novel NAC transcription factor (TF) gene in apple related to plant dwarfing.

Melatonin mediates the regulation of ABA metabolism, free-radical scavenging, and stomatal behaviour in two Malus species under drought stress.

Melatonin pre-treatment significantly increases the tolerance of both drought-tolerant Malus prunifolia and drought-sensitive M. hupehensis plants. Its beneficial effects include better water conservation in leaves, less electrolyte leakage, steady chlorophyll contents, and greater photosynthetic performance under stress conditions.

Dopamine alleviates salt-induced stress in Malus hupehensis.

Dopamine mediates many physiological processes in plants. We investigated its role in regulating growth, ion homeostasis and the response to salinity in Malus hupehensis Rehd. Both hydroponics and field-pot experiments were conducted under saline conditions.

The mitigation effects of exogenous melatonin on salinity-induced stress in Malus hupehensis.

As an indoleamine molecule, melatonin mediates many physiological processes in plants. We investigated its role in regulating growth, ion homeostasis, and the response to oxidative stress in Malus hupehensis Rehd. under high-salinity conditions.