Sorbitol in loquat promotes early flower bud differentiation via the MADS-box transcription factor EjCAL

AbstractThe sugar alcohol sorbitol plays an important signaling role in fruit trees. Here, we found that sorbitol significantly increased during flower bud differentiation (FBD) in loquat (Eriobotrya japonica Lindl.) from the physiological FBD stage (EjS1) to the morphological FBD stage (EjS2), and it then decreased in the panicle development stage (EjS3) compared to in EjS2, and in subsequent stages. Spraying sorbitol increased the sorbitol content and thereby promoted early FBD and increased the proportion of flower buds that completed FBD. A transcriptomics analysis showed that the expression of a MADS-box transcription factor (TF) family gene, EjCAL, was highly correlated with the FBD phenotypic data. EjCAL-overexpressing transgenic tobacco exhibited the early FBD phenotype. Using the EjCAL promoter as bait in a yeast-one hybrid (Y1H) assay, the TF ERF12 was identified. Chromatin immunoprecipitation (ChIP)-PCR confirmed that EjERF12 can bind to the EjCAL promoter, and β-glucuronidase (GUS) activity assays demonstrated that EjERF12 can regulate EjCAL expression. Spraying loquat with sorbitol confirmed that EjERF12 and EjCAL expression were regulated by sorbitol. We also identified downstream functional genes (EjUF3GaT1, EjGEF2, and EjADF1) that might be involved in FBD. Finally, we found that the change in the level of hyperoside (a reproduction-related flavonoid) was consistent with that of sorbitol during FBD in loquat, and EjCAL can bind to the EjUF3GaT1 promoter and might thereby regulate hyperoside biosynthesis. Two early- and late-flowering varieties of loquat and EjCAL-overexpressing transgenic tobacco plants were used to confirm this hypothesis.One-sentence summarySorbitol promotes bud differentiation via EjCAL.

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Phenotypic Evaluation of a Hybrid Diploid Blueberry Population for Plant Development and Fruit Quality Traits

Agronomy ◽

10.3390/agronomy10081067 ◽

2020 ◽

Vol 10 (8) ◽

pp. 1067

Author(s):

Lisa J. Rowland ◽

Elizabeth L. Ogden ◽

Bryan T. Vinyard

Keyword(s):

Fruit Quality ◽

Plant Development ◽

Cold Hardiness ◽

Soluble Solids ◽

Chilling Requirement ◽

Quality Traits ◽

Flower Bud ◽

Phenotypic Data ◽

Fruit Quality Traits ◽

Highly Correlated

A diploid blueberry mapping population, used previously to map quantitative trait loci (QTL) for chilling requirement and cold hardiness, was evaluated for several plant development and fruit quality traits. Specifically, the population was phenotyped in a greenhouse for timing of various stages of flower bud, leaf bud and fruit development and for fruit quality traits including weight, diameter, color, scar, firmness, flavor and soluble solids. Phenotypic data was analyzed statistically by analysis of variance, correlation tests, to examine associations of traits, and heritability. Results indicated that the traits were segregating and most were distributed normally in the population. Many of the development traits were correlated, and timing of shoot expansion, early bloom and full bloom was also correlated with the previously evaluated trait of chilling requirement. Some correlations were found among the fruit quality traits as well. For example, weight was highly correlated with diameter, and subjectively measured firmness was moderately correlated with one of the objectively measured firmness traits. In addition, most of the traits showed significant variation across genotypes and across years, and most had moderate to high heritability. Therefore, we conclude that the diploid population should be useful for identifying QTL for many of these traits.

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Alternative splicing of the dormancy-associated MADS-box transcription factor gene PpDAM1 is associated with flower bud dormancy in ‘Dangshansu’ pear (Pyrus pyrifolia white pear group)

Plant Physiology and Biochemistry ◽

10.1016/j.plaphy.2021.07.017 ◽

2021 ◽

Author(s):

Jianzhao Li ◽

Xinhui Yan ◽

Mudassar Ahmad ◽

Wenjie Yu ◽

Zhizhong Song ◽

...

Keyword(s):

Transcription Factor ◽

Alternative Splicing ◽

Bud Dormancy ◽

Pyrus Pyrifolia ◽

Mads Box ◽

Transcription Factor Gene ◽

Flower Bud ◽

Factor Gene

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Transcription factor TCP20 regulates peach bud endodormancy by inhibiting DAM5/DAM6 and interacting with ABF2

Journal of Experimental Botany ◽

10.1093/jxb/erz516 ◽

2019 ◽

Vol 71 (4) ◽

pp. 1585-1597 ◽

Cited By ~ 2

Author(s):

Qingjie Wang ◽

Gongxun Xu ◽

Xuehui Zhao ◽

Zejie Zhang ◽

Xuxu Wang ◽

...

Keyword(s):

Transcription Factor ◽

Prunus Persica ◽

Regulatory Mechanism ◽

Deciduous Tree ◽

Mads Box ◽

Flower Bud ◽

Mobility Shift ◽

Electrophoretic Mobility Shift Assays ◽

Proliferating Cell ◽

Hybrid Screening

Abstract The dormancy-associated MADS-box (DAM) genes PpDAM5 and PpDAM6 have been shown to play important roles in bud endodormancy; however, their molecular regulatory mechanism in peach is unclear. In this study, by use of yeast one-hybrid screening, we isolated a TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR transcription factor, PpTCP20, in the peach cultivar ‘Zhongyou 4’ (Prunus persica var. nectarina). The protein was localized in the nucleus and was capable of forming a homodimer. Electrophoretic mobility shift assays demonstrated that PpTCP20 binds to a GCCCR element in the promoters of PpDAM5 and PpDAM6, and transient dual luciferase experiments showed that PpTCP20 inhibited the expression of PpDAM5 and PpDAM6 as the period of the release of flower bud endodormancy approached. In addition, PpTCP20 interacted with PpABF2 to form heterodimers to regulate bud endodormancy, and the content of abscisic acid decreased with the release of endodormancy. PpTCP20 also inhibited expression of PpABF2 to regulate endodormancy. Taken together, our results suggest that PpTCP20 regulates peach flower bud endodormancy by negatively regulating the expression of PpDAM5 and PpDAM6, and by interacting with PpABF2, thus revealing a novel regulatory mechanism in a perennial deciduous tree.

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The Role of EjSPL3, EjSPL4, EjSPL5, and EjSPL9 in Regulating Flowering in Loquat (Eriobotrya japonica Lindl.)

International Journal of Molecular Sciences ◽

10.3390/ijms21010248 ◽

2019 ◽

Vol 21 (1) ◽

pp. 248

Author(s):

Yuanyuan Jiang ◽

Jiangrong Peng ◽

Man Wang ◽

Wenbing Su ◽

Xiaoqing Gan ◽

...

Keyword(s):

Transcription Factors ◽

Flowering Time ◽

Sequence Similarity ◽

Fruit Trees ◽

Eriobotrya Japonica ◽

Regulation Mechanism ◽

Flower Bud ◽

High Sequence Similarity ◽

Flowering Genes ◽

Flowering Regulation

The age pathway is important for regulating flower bud initiation in flowering plants. The major regulators in this pathway are miR156 and SPL transcription factors. To date, SPL genes have been identified in many species of plants. Loquat, as a woody fruit tree of Rosaceae, is unique in flowering time as it blooms in winter. However, the study of its SPL homologous genes on the regulation mechanism of flowering time is still limited. In this study, four SPL homologs—EjSPL3, EjSPL4, EjSPL5, and EjSPL9—are cloned from loquat, and phylogenetic analysis showed that they share a high sequence similarity with the homologues from other plants, including a highly conserved SQUAMOSA promoter binding protein (SBP)-box domain. EjSPL3, EjSPL4, EjSPL5 are localized in the cytoplasm and nucleus, and EjSPL9 is localized only in the nucleus. EjSPL4, EjSPL5, and EjSPL9 can significantly activate the promoters of EjSOC1-1, EjLFY-1, and EjAP1-1; overexpression of EjSPL3, EjSPL4, EjSPL5, and EjSPL9 in wild-type Arabidopsis thaliana can promote flowering obviously, and downstream flowering genes expression were upregulated. Our work indicated that the EjSPL3, EjSPL4, EjSPL5, and EjSPL9 transcription factors are speculated to likely participate in flower bud differentiation and other developmental processes in loquat. These findings are helpful to analyze the flowering regulation mechanism of loquat and provide reference for the study of the flowering mechanism of other woody fruit trees.

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Ultrastructural Changes in Apical Meristem during Flower Bud Differentiation of Japanese Pear, Pyrus pyrifolia Nakai

Engei Gakkai zasshi ◽

10.2503/jjshs.63.323 ◽

1994 ◽

Vol 63 (2) ◽

pp. 323-333 ◽

Cited By ~ 1

Author(s):

Shu-Ang Peng ◽

Shuichi Iwahori

Keyword(s):

Apical Meristem ◽

Japanese Pear ◽

Ultrastructural Changes ◽

Pyrus Pyrifolia ◽

Flower Bud ◽

Pyrus Pyrifolia Nakai ◽

Flower Bud Differentiation

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A MADS-Box Transcription Factor Related to Fertility Conversion in Male Sterile Wheat Lines

ACTA AGRONOMICA SINICA ◽

10.3724/sp.j.1006.2008.00598 ◽

2008 ◽

Vol 34 (4) ◽

pp. 598-604 ◽

Cited By ~ 3

Author(s):

Lin-Lin ZHOU

Keyword(s):

Transcription Factor ◽

Mads Box ◽

Male Sterile ◽

Wheat Lines

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Hybrid Triploid Induced by Megaspore Chromosome Doubling in Jujube (Ziziphus jujuba Mill.) ‘Maya’ and Its Characteristics

Forests ◽

10.3390/f12020112 ◽

2021 ◽

Vol 12 (2) ◽

pp. 112

Author(s):

Songshan Liu ◽

Chenxing Zhang ◽

Weicong Yang ◽

Xiang Li ◽

Lu Hou ◽

...

Keyword(s):

Chromosome Doubling ◽

Colchicine Treatment ◽

Fruit Trees ◽

Growth Stress ◽

Optimal Timing ◽

Photosynthetic Parameters ◽

Flower Bud ◽

Treatment Methods ◽

Triploid Individual ◽

Colchicine Solution

Polyploid breeding is an important strategy for tree improvement because polyploid individuals typically show superior traits, such as improved growth, stress resistance, and superior fruit quality. Artificial induction of chromosome doubling of female gametes is an effective approach to obtain triploid progeny. However, no triploid fruit tree cultivars have been developed using this approach. The objective of this study was to explore the utility of chromosome doubling in female gametes of ‘Maya’ jujube to produce triploid individuals. The temporal relationship between flower bud morphology and the megaspore meiotic stage was studied to guide the optimal timing of colchicine treatment. Colchicine solution was applied to bearing shoots of mature ‘Maya’ jujube trees in a field experiment using two treatment methods (improved cotton leaching and injection method) and three concentrations (0.3%, 0.4%, and 0.5%). The water transport rate of ‘Maya’ jujube shoots was studied using dye solution to judge the effectiveness and timing of the colchicine treatment methods. Two triploids were identified among the progenies from the colchicine-treated shoots. The highest efficiency of triploid production was 3.3% when flower buds of diameter 1.76–2.12 mm were treated with 0.3% colchicine solution for 4 h using an improved cotton leaching method. The ground diameter, plant thorn length, leaf width, leaf area, stomatal length, stomatal width, chlorophyll content, and photosynthetic parameters of one triploid individual were significantly higher than those of diploids of identical parentage at 18 months old. Thus, induction of 2n megaspores is an effective approach to generate triploid jujube. These results are expected to promote and accelerate triploid breeding in fruit trees.

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