PbGIF1 promoting cell-proliferation in pear fruit is transcriptionally activated by Pb RR1

As a cell proliferation regulator involved in wide biological processes in plants,GRF-INTERACTING FACTOR(GIF)controls different tissues development.However,whether GIF participates in fruit development remains unclear.According to transcriptome data,we identified PbGIF1was highly expressed during fruit development in cytokinins induced parthenocarpy pear.In the present study,the biofunction of PbGIF1 was initially verified.Overexpression of PbGIF1 promoted fruit size of transgenic tomato.The size of flesh fruit was not affected by cell expansion but the cell proliferation was promoted by overexpressing Pb GIF1.The accelerated cell proliferation process was also observed in PbGIF1-overexpressed transgenic pear fruit calli.The transcriptional regulation of cytokinins on PbGIF1 was further confirmed by exogenous CPPU treatments in pear fruitlets.To investigate the underlying mechanism,the cytokinins-responded factor,PbRR1,was further focused on.The results of Yeast-one-hybrid assay suggested that PbRR1 can bind to the promoter sequence of PbGIF1.The transcriptional activation of PbRR1 on PbGIF1 was also confirmed by Dual-Luciferase assays.Taken together,the results showed that cytokinins control pear fruit development via the transcriptional activation of PbGIF1 by PbRR1.

Ultrastructure of Epidermis and Flesh of the Developing Apple Fruit

The ultrastructure of the epidermis and flesh of apple ( Malus domestica Borkh cv. Red Fuji) fruit was systematically observed during the fruit development via transmission electron microscopy. The results showed that, in spite of the ultrastructural changes in many aspects of the developing fruit epidermal cells, it remained almost unchanged throughout the whole developmental process that the cytoplasm was filled with numerous endoplasmic reticula (ER). Most of these endoplasmic reticula were tube_like and rough_ER with enlarged cisterna from which many vesicles were produced. Some of the vesicles were shown to merge into vacuole. Some dynamic Golgi bodies were also found. All the ultrastructural characteristics showed that the epidermal cells have the features of excretory cells. The ultrastructure of the fruit flesh cells at the young fruit stage were shown to be metabolically active, characterized by the presence of numerous clustered plasmodesmata, cisterna enlarged_ and rough_ER filling the cytoplasm, plenty of vesicles and Golgi bodies, indicating their dynamic cellular transport function. Some giant_circular rough_ERs were found. All the ultrastructural features at this early developmental stage should be closely associated with the enlargement of the young fruit. At the rapid growing phase of the fruit the main changes were characterized by: the starch grain_filled amyloplasts, furcating of the single orifice of plasmodesmata, and the cytoplasm enrichment of both the Golgi body_formed vesicles and other vesicles. These features correspond well with those of a photoassimilate sink_cell. An ultrastructural degeneration phenomenon was observed at the fruit ripening stage, but the mitochondria and plasmalemma still remained intact, which might be related to the continuous development of fruit quality during the fruit ripening.

Variation of Sugar, Acid and Vitamin C Contents in Fruit Development in Different Types of Kiwifruit

The variation of sugar, acid and vitamin C contents in fruits of red flesh kiwifruit （Actinidia chinensis） ＂Hongyang＂ and green fresh kiwifruit （A. deliciosa） ＇Jinkui＇ were investigated during fruit development. The results showed that the to- tal sugar soluble contents of ＂Hongyang＇ and ＇Jinkui＂ during fruit development ex- isted different variations. With the upward trend of ＇Hongyang＇ fruit development, 95 days after full bloom （DAFB）, the total soluble sugar accumulation was relatively slow, and then rose rapidly until harvest with the maximum content （6.87%）. While ＇Jinkui＇ fruit showed a fluctuant process, rising in 50 DAFB, then declining, then rising rapidly and decreasing slightly right before harvest. The variation of fruit titrat- able acid between them was more consistent, which was increased and then de- creased. The only difference was that the titratable acid content of ＇Jinkui＇ fruit de- creased slowly from the late of fruit development to fruit ripening, similar to the maximum value, but that of ＇Hongyang＇ fruit decreased rapidly in the late. Titrat- able acid contents of them in the maturity were 1.08% and 1.20%, respectively. The trends of sugar acid ratio for ＇Hongyang＇ and ＇Jinkui＇ fruit were quite different. ＇Hongyang＇ fruit increased slowly and then rapidly; ＇Jinkui＇ changed from decreas- ing to increasing, followed by slight decreasing in mature stage. In addition, the two kiwifruit varieties had a similar change trend of Vc content during fruit development, which changed from rapid increasing to declining, followed by slight growing in the harvest. The changing tendency of ＇Jinkui＇ fruit was later than that of ＇Hengyang＇.

Dynamic Changes of Endogenous Hormone Content in Dangshansu Pear during Fruit Development

[Objective] The aim was to clear the relationship between fruit growth and development and endogenous hormones content in the pulp of Dangshansu pear.[Method] Choosing Dangshansu pear as material,the dynamic changes of endogenous hormones in pulp during various development stages were determined by means of enzyme linked immunosorbent assay（ELISA）.[Result] The results indicated that the content of endogenous hormones like ZR,GA and IAA promoting fruit growth showed increase trend within 15 d after pollination,and higher content of ZR,GA and IAA could promote ovary development and normal fruit setting of Dangshansu pear.The content of ZR in pulp had the highest value at the beginning of the first fast growth period,and then showed decrease trend until fruit became mature.The dynamic changes of IAA and GA were similar,namely their contents were higher in the first fast growth period,and decreased with fruit development,and then increased rapidly and was up to the maximum value in the second fast growth period,corresponding with the growth dynamic of fruit.The peaks of ABA content could be found on the 15th,45th and 120th day after pollination,which corresponded with the physiological fruit dropping and maturing period of Dangshansu pear.[Conclusion] The duration of various development periods and content of endogenous hormones of Dangshansu pear were different,and fruit growth and development were closely related to the content of endogenous hormones.

Physio-Biochemical Changes in Jujube Fruits(Zizyphus jujuba Mill. cv. Lingwuchangzao) at Mature Stage

The changes of physiological and biochemical indices in jujube fruits during the late development were investigated from 6-year-old jujube trees （Zizyphus jujuba Mill. cv. Lingwuchangzao）. The results showed that the flesh firmness decreased slowly from white-green stage to full-red stage, being significantly related with the developmental maturity of jujube fruits negatively, the correlation coefficient reached -0.980 3^＊＊. The contents of ascorbic acid and titratable acid in jujube fruits were significantly related with the developmental process of jujube fruits negatively or positively, the correlation coef- ficients were -0. 973 1^＊＊and ＋ 0. 974 6^ ＊ ＊ , respectively. The contents of soluble solids, total sugar, and sucrose increased with jujube ripening, while the relative sweetness of jujube fruits showed the same variation pattern, the correlation coefficients were 0. 996 6 ^＊ ＊ , 0. 988 0^＊＊ , and 0. 982 8 ^＊ ＊ , respectively. Before white-green stage during fruit development, the accumulation of monosaccharide was predominant in jujube fruits, following a fast accumulation of sucrose, indicating that the main component of sugars is sucrose at the crisp-ripe stage. Furthermore, the starch content of the flesh reached the peak at about thirty percentage of jujube maturity, being 51,54 mg/100 g.FW. The respiratory rates varied between 10 mg/（ kg.h） and CO2 26 mg/（ kg.h） after fruit turning red and before softening, indicating a non-climacteric respiratory type.

Flowering Biology and Fruit Development Characteristics of Apricot Cultivar ‘Kezilang' in Xinjiang

The flowering biology and fruit development characteristics of a Xinjiang apricot （Armeniaca vulgaris Lam） cultivar Kezilang were studied by measuring its flowering phenology, floral organ development, stigma receptivity, pollen quantity, pollen viability, fruit diameter, fruit fresh weight, fruit dry weight and fruit contents, with an attempt to provide a theoretical basis for the cultivation and promotion of Kezilang. The results showed that Kezilang can be popularized as an early-maturing apricot cultivar, as it had high fruit setting rate, large fruit weight, excellent taste, high sugar content and lower titratable acid content in fruit. The dynamic curves of Kezilang fruit diameters in three directions, fruit fresh weight and fruit dry weight were all S-shaped, and the rapid growth stage of dry weight was later than that of other terms. Fruit swelling was due to higher water content of flesh tissue in early stage of the rapid growth periods of fruit. Most sugar in flesh was accumulated at the second rapid growth period of fruit.

Changes of Aroma Components in Hongdeng Sweet Cherry During Fruit Development

To study the changes of aroma components in sweet cherry during fruit development, the aroma components in sweet cherry fruit from the green stage, the color stage, the commercial stage, and the ripe stage were collected using head-space solid phase microextraction （HS-SPME）, and were analyzed using a gas chromatograph-mass spectrophotometer （GC- MS）. A total of 37 compounds were identified from the sample extracts. Aldehydes, alcohols, and esters were the major constituents. The aroma components behaved differently during the fruit developmental period. C6 aldehydes and aromatic aldehydes were the main aldehydes in the sweet cherry fruit. The contents of C6 aldehydes increased quickly to 84.16% in the color stage, then decreased as ripening proceeded, and then, the contents decreased to 59.20 and 55.58% at the commercial stage and the ripe stage, respectively. The aromatic aldehydes （benzaldehyde） increased as ripening proceeded, and the maximum was found at the ripe stage. Alcohols of sweet cherry fruit included C6 alcohols and aromatic alcohols. The content of （E）-2-hexen-l-ol increased as ripening proceeded. The maximum was found at the commercial stage; alcohol was only found at the ripe stage. Ester components included ethyl acetate, butanoic acid ethyl ester, hexanoic acid ethyl ester, which increased as the fruit ripened. Hexanal, （E）-2-hexenal, benzaldehyde, （E）-2-hexen-l-ol, ethyl acetate, and hexanoic acid ethyl ester were the characteristic aroma components of sweet cherry fruit. These aroma components started to form drastically at the color stage, and the main aroma was formed at the commercial stage, which then turned bad at the ripe stage because of the presence of alcohol. So the optimal harvest time of sweet cherry was at the commercial stage.

Effect of Nitrogen on Apple Fruit Development in Different Loads

The experiments including soil application N, thinning and priming leaf treatment, using eight -year-old apple trees (M. domestica Borkh.cv.Red Fuji/ M. hupenensis Rhed) as materials were carried out to study the effect of N on fruit development. The main results were as follows: on heavily thinned trees, SS activity was independent of N and priming leaves treatments. The results show that the carbohydrate restriction of source to sink activity did not exist, and N application did not stimulate fruit growth rates relative to those on nonfertilized trees; however, N fertilization resulted in a longer fruit development period and increased the growth potential of individual fruit by 20.8% (fresh weight) and 14.1% (dry weight) vs. controls ; in unthinned trees, SS activity was increased by N fertilization but decreased by priming leaves treatment , so the carbohydrate restriction of source to sink activity existed, N fertilization increased the average single fruit weight both by extending the fruit development period and by increasing fruit growth rate, and the increasing rates were 28.2% (fresh weight) and 19.4 % (dry weight) compared to the unthinned nonfertilized controls. Fruit soluble sugar and pericarp anthocyanin concentration was decreased by N fertilization.

Haloxylon ammodendron (Amaranthaceae) fruit development delay caused by post-flowering non-inductive photoperiod

Haloxylon ammodendron （C. A. Mey.） is one of the economically and ecologically important desert trees used for sand fixation. The ovary of H. ammodendron is found not to swell after flowering in spring until at the end of August or early September in western China. However, what happens for ovary at anatomic level in that period and which crucial ecological factor regulates the phenomenon of H. ammodendron have not been fully understood. To characterize the phenomenon and explore the crucial environmental regulating factors, we carried out the morphological and anatomic observations at the different development stages of the fruits and three single-factor experiments （low air temperature, sufficient soil moisture, and short day length）. Our results showed that under the natural conditions, the ovary of H. ammodendron after flowering developed slowly and the morphological changes of fruits were not significant for the period from May to August and after late August or early September; and then the ovary developed rapidly and matured in October. Cell division in embryo was observed to start approximately 25 days after flowering （DAF） and just developed to globular embryo stage at mid-August. Photoperiod was identified as the pivotal environmental factor regulating the fruit development of H. ammodendron. Moreover, the threshold value of day length for the fruit development was 14.0 h. A long day （〉14.0 h） treatment began from 5 DAF could delay fruit development of H. ammodendron while a short day （〈14.0 h） treatment could accelerate it. Moreover, a further longer day treatment （〉15.0 h） could also delay fruit development even when they had developed for a long time （110 DAF）. The present study indicated that H. ammodendron adopted a reproductive strategy of delayed fruit development and this strategy helps it survive and obtain offspring in harsh desert habitats.

Changes of Endogenous Hormone Contents in Fruit, Seeds and Their Effects on the Fruit Development of Rosa roxburghii

The fruit of cultivar Guinong5 (Rosa roxburghii Tratt.) was used to investigate the regularity of its growth and development, and the changes of endogenous hormone contents during the period of the growth and development. The result showed that contents of GA 1+3, IAA and ZRs in the flower receptacle of young fruit were high and then decreased, contents of GA 1+3and IAA in seeds increased with its development until maturity. The contents of ZRs and ABA in the flower receptacle of young fruits and seeds were high, and then had a tendency of descent with the development of fruits. The contents of GA 1+3, IAA, ZRs and ABA in flower receptacle of young fruit with normal fertilization were much higher than those of in non-fertilization fruits. In the flower receptacle of malformed fruits, the contents of GA 1+3, IAA and ZRs in normally developing flower receptacle were significantly higher than those in malformed fruits. The growth and development of fruits depended largely on the seeds, development because the seeds in the fruits with non-fertilization failed to be formed or even formed but irreproducible, which would lead to the decrease of GA 1+3, IAA contents and the abnormal development of fruits. Therefore the fruits deformed and dropped inevitably.

Characterization of fruit development and kernel component variation in candlenut （Aleurite moluccana）

Candlenut （Aleurites moluccana） is an important woody oil plant in the tropi-cal and subtropical regions. In the present study, characteristics of fruit development and changes of kernel components in candlenut during its fruiting season were investigated. It indicate that in southern China the growth and development period of candlenut fruit is from March to September. The period of rapid fruit growth occurs in late March to mid-May. Proteins and fats of mature nuts are accumulated in a critical period during the mid to late fruit development cycle. The optimal period for harvest is mid-August to late September. During fruit development, seed moisture content showed a trend of gradual decrease; it dropped from the initial 96.1% at the early stages of development to 16.9% at maturity. Sol-uble protein and sugar content showed a gradual increase during the initial and mid devel-opment period; it peaked in July and then decreased gradually. Starch content showed a rapid increase and accumulation during the initial and mid development period; it peaked in June, and then rapidly dropped. However, fat content increased continuously as the fruit developed and matured, and the maximum rate of lipid accumulation occurred in the mid-dle stage of fruit development. The preliminary conclusion of this study laid a foundation for making full use of candlenut fruit, especially as biofuels.

Anatomical Study an the Development of Strawberry Fruit

The development of strawberry fruit, two cultivars-Gelila and Xiaoshi, was systematically studied by anatomical and embryological methods. The growth dynamics of fruit showed that the two cultivars performed similar changes with their fresh weight volume and structure, it included the first slow growth stage, the rapid growth stage and the second solw growth stage. The fruit was a typical polyachene with a ovule which belonged to a Poligonum type, the growth process of pollen tube from stigma to embryo sac was clearly observed by flourescence microscopy. Embryo development was similar to that of most dicotyls, and the mature embryo was orthotropous; Endosperm development was a nuclear type, and gradually disappeared with development:Seed coat consisted of 34 layer cells, and pericarp was composed of 68 layer cells which differentiated from ovary wall cell; The structure of receptacle was a typical stem which consisted of epidermis ,cortex and vascular cylinder. With development, the cortex an

Analysis of Aromatic Components in Fruit of Apricot Cultivar Jinkaite in Different Development Periods

The aromatic components and contents in fruit of apricot cultivar Jinkaite were analyzed in green ripe period, commercial ripe period and full ripe period by static headspace and gas chromatography-mass spectrometry. The results showed that total 46 kinds of aromatic components were detected in Jinkaite apricot fruit. The main aromatic components included esters, alcohols, hydrocarbons and aldehydes. The aromatic components and contents had significant differences be- tween various fruit developmental periods. Specifically, 31,32 and 24 kinds of aromatic components were detected in green ripe period, commercial ripe period and full ripe period, respectively. The contents of esters were the highest at the 3 developmental stages with the percentages of 61.14%, 70. 02% and 61.48%, respec- tively. Hexyl acetate, ethyl hexanoate, hexyl 2-methyl propionate and 1-hexanol were characteristic aromatic components in fruit of apricot Jinkaite, and their aroma values in full ripe period were 448.50, 29.86, 7.85 and 3.54, respectively.

Effects of Xenia on Fruit and Seed in <i>Vernicia fordii</i>

Tung tree, Vernicia fordii, is a plant species producing industrial oil (tung oil). Although the cultivation of the tung tree produces great economic value, some important genetic and physiological traits in V. fordii have not been fully recognized. As one of them, the effect of pollen on the maternal plant (xenia) is unknown in V. fordii, which is an important part of the efficient cultivation system of many crops. This study performed hybridization with three important tung cultivars (Dami, Xiaomi and Putao) to evaluate the influence of pollen source on fruit and seed development. The results revealed that xenia is present in V. fordii, which influences fruit setting, fruit size, seed weight and oil content. Among the cultivars investigated, the hybridization combination with Putao as a female parent and Dami as male parent showed significant improvement of seed yield and oil content than self-pollination, which could be considered to apply in practice.

Heat stress impairs floral meristem termination and fruit development by affecting the BR-SlCRCa cascade in tomato

Floral meristem termination is a key step leading to carpel initiation and fruit development.The frequent occurrence of heat stress due to global warming often disruptsfloral determinacy,resulting in defective fruit formation.However,the detailed mechanism behind this phenomenon is largely unknown.Here,we identify CRABS CLAW a(SlCRCa)as a key regulator offloral meristem termination in tomato.SlCRCa func-tions as an indispensablefloral meristem terminator by suppressing SlWUS activity through the TOMATO AGAMOUS 1(TAG1)–KNUCKLES(SlKNU)–INHIBITOR OF MERISTEM ACTIVITY(SlIMA)network.A direct binding assay revealed that SlCRCa specifically binds to the promoter and second intron of WUSCHEL(SlWUS).We also demonstrate that SlCRCa expression depends on brassinosteroid homeostasis in theflo-ral meristem,which is repressed by heat stress via the circadian factor EARLY FLOWERING 3(SlELF3).These results provide new insights intofloral meristem termination and the heat stress response inflowers and fruits of tomato and suggest that SlCRCa provides a platform for multiple protein interactions that may epigenetically abrogate stem cell activity at the transition fromfloral meristem to carpel initiation.

Accumulation of Carbohydrate and Regulation of 14-3-3 Protein on Sucrose Phosphate Synthase(SPS) Activity in Two Tomato Species

To explore the differences of carbohydrate metabolism in two tomato species and discuss the possible regulation of 14-3-3 proteins on the sucrose phosphate synthase （SPS） activity, we determined the contents of soluble sugar and starch through high performance liquid chromatography （HPLC）. The activities of sugar-metabolizing enzymes were assayed in desalted extract, and the relative expression levels of related genes in sugar metabolism were determined though real-time RT-PCR. The results indicated that glucose and fructose were mainly accumulated during the maturation of the fruit because of the high acid invertase （AI） and neutral invertase （NI） in Micro-Tom （Solanum lycopersicum） fruit, while in Solanum chmielewskii fruit, SPS which went along with the change of sucrose content led to the rapid sucrose increase during the fruit ripening. TFT1 and TFT10, belonging to 14-3-3 protein in tomato, were likely to down-regulated SPS activity during young and intumescence period.

Genome-wide analysis of OVATE family proteins in cucumber(Cucumis sativus L.)

OVATE family proteins(OFPs)are plant-specific proteins with a conserved OVATE domain that regulate plant growth and development.Although OFPs have been studied in several species,their biological functions remain largely unknown in cucumber(Cucumis sativus L.).This study identified 19 Cs OFPs distributed on seven chromosomes in cucumber.Most Cs OFP genes were expressed in reproductive organs,but with different expression patterns.Ectopic expression of Cs OFP12-16c in Arabidopsis resulted in shorter and blunt siliques.The overall results indicated that Cs OFP12-16c regulates silique development in Arabidopsis and may have a similar function in cucumber.

Tomato Fruit Development and Ripening Are Altered by the Silencing of LeEIN2 Gene

Loss-of-function ethylene insensitive 2 （EIN2） mutations showed ethylene insensitivity in Arabidopsis, which indicated an essential role of EIN2 in ethylene signaling. However, the function of EIN2 in fruit ripening has not been investigated. To gain a better understanding of EIN2, the temporal regulation of LeEIN2 expres- sion during tomato fruit development was analyzed. The expression of LeEIN2 was constant at different stages of fruit development, and was not regulated by ethylene. Moreover, LeEIN2-silenced tomato fruits were developed using a virus-induced gene silencing fruit system to study the role of LeEIN2 in tomato fruit ripening. Silenced fruits had a delay in fruit development and ripening, related to greatly descended expression of ethylene-related and ripening-related genes in comparison with those of control fruits. These results suggested LeEIN2 positively mediated ethylene signals during tomato development. In addition, there were fewer seeds and Iocules in the silenced fruit than those in the control fruit, like the phenotype of parthenocarpic tomato fruit. The content of auxin and the expression of auxin-regulated gene were declined in silenced fruit, which indicated that EIN2 might be important for crosstalk between ethylene and auxin hormones.

Identification of Regulatory DNA Elements Using Genome-wide Mapping of DNase I Hypersensitive Sites during Tomato Fruit Development

Development and ripening of tomato fruit are precisely controlled by transcriptional regulation, which de- pends on the orchestrated accessibility of regulatory proteins to promoters and other c/s-regulatory DNA elements. This accessibility and its effect on gene expression play a major role in defining the develop- mental process. To understand the regulatory mechanism and functional elements modulating morpholog- ical and anatomical changes during fruit development, we generated genome-wide high-resolution maps of DNase I hypersensitive sites （DHSs） from the fruit tissues of the tomato cultivar ＂Moneymaker＂ at 20 days post anthesis as well as break stage. By exploring variation of DHSs across fruit development stages, we pinpointed the most likely hypersensitive sites related to development-specific genes. By detecting binding motifs on DHSs of these development-specific genes or genes in the ascorbic acid biosynthetic pathway, we revealed the common regulatory elements contributing to coordinating gene transcription of plant ripening and specialized metabolic pathways. Our results contribute to a better understanding of the regulatory dynamics of genes involved in tomato fruit development and ripening.