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<front>
<journal-meta>
<journal-id journal-id-type="publisher-id">Front. Plant Sci.</journal-id>
<journal-title>Frontiers in Plant Science</journal-title>
<abbrev-journal-title abbrev-type="pubmed">Front. Plant Sci.</abbrev-journal-title>
<issn pub-type="epub">1664-462X</issn>
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<publisher-name>Frontiers Media S.A.</publisher-name>
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<article-meta>
<article-id pub-id-type="doi">10.3389/fpls.2024.1413866</article-id>
<article-categories>
<subj-group subj-group-type="heading">
<subject>Plant Science</subject>
<subj-group>
<subject>Editorial</subject>
</subj-group>
</subj-group>
</article-categories>
<title-group>
<article-title>Editorial: Molecular mechanisms of fruit quality formation in fruit trees</article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author" corresp="yes">
<name>
<surname>Wang</surname>
<given-names>Lihu</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
<xref ref-type="author-notes" rid="fn001">
<sup>*</sup>
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<contrib contrib-type="author" corresp="yes">
<name>
<surname>Wang</surname>
<given-names>Lixin</given-names>
</name>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
<xref ref-type="author-notes" rid="fn001">
<sup>*</sup>
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<contrib contrib-type="author" corresp="yes">
<name>
<surname>Peng</surname>
<given-names>Ze</given-names>
</name>
<xref ref-type="aff" rid="aff3">
<sup>3</sup>
</xref>
<xref ref-type="author-notes" rid="fn001">
<sup>*</sup>
</xref>
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</contrib>
<contrib contrib-type="author" corresp="yes">
<name>
<surname>Fei</surname>
<given-names>Xitong</given-names>
</name>
<xref ref-type="aff" rid="aff4">
<sup>4</sup>
</xref>
<xref ref-type="author-notes" rid="fn001">
<sup>*</sup>
</xref>
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<contrib contrib-type="author" corresp="yes">
<name>
<surname>Wei</surname>
<given-names>Hairong</given-names>
</name>
<xref ref-type="aff" rid="aff5">
<sup>5</sup>
</xref>
<xref ref-type="author-notes" rid="fn001">
<sup>*</sup>
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<uri xlink:href="https://loop.frontiersin.org/people/36027"/>
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</contrib-group>    <aff id="aff1">
<sup>1</sup>
<institution>School of Landscape and Ecological Engineering, Hebei University of Engineering</institution>, <addr-line>Handan</addr-line>, <country>China</country>
</aff>
<aff id="aff2">
<sup>2</sup>
<institution>College of Horticulture, Hebei Agricultural University</institution>, <addr-line>Baoding, Hebei</addr-line>, <country>China</country>
</aff>
<aff id="aff3">
<sup>3</sup>
<institution>College of Horticulture, South China Agricultural University</institution>, <addr-line>Guangzhou</addr-line>, <country>China</country>
</aff>
<aff id="aff4">
<sup>4</sup>
<institution>College of Forestry, Northwest Agriculture and Forestry University</institution>, <addr-line>Xianyang</addr-line>, <country>China</country>
</aff>
<aff id="aff5">
<sup>5</sup>
<institution>College of Forest Resources and Environmental Science, Michigan Technological University</institution>, <addr-line>Houghton, MI</addr-line>, <country>United States</country>
</aff>
<author-notes>
<fn fn-type="edited-by">
<p>Edited and Reviewed by: Peng Wang, Jiangsu Province and Chinese Academy of Sciences, China</p>
</fn>
<fn fn-type="corresp" id="fn001">
<p>*Correspondence: Lihu Wang, <email xlink:href="mailto:wanglihu@hebeu.edu.cn">wanglihu@hebeu.edu.cn</email>; Lixin Wang, <email xlink:href="mailto:wanglxht@163.com">wanglxht@163.com</email>; Ze Peng, <email xlink:href="mailto:zepeng@scau.edu.cn">zepeng@scau.edu.cn</email>; Xitong Fei, <email xlink:href="mailto:feixitong@nwafu.edu.cn">feixitong@nwafu.edu.cn</email>; Hairong Wei, <email xlink:href="mailto:hairong@mtu.edu">hairong@mtu.edu</email>
</p>
</fn>
</author-notes>
<pub-date pub-type="epub">
<day>09</day>
<month>05</month>
<year>2024</year>
</pub-date>
<pub-date pub-type="collection">
<year>2024</year>
</pub-date>
<volume>15</volume>
<elocation-id>1413866</elocation-id>
<history>
<date date-type="received">
<day>08</day>
<month>04</month>
<year>2024</year>
</date>
<date date-type="accepted">
<day>30</day>
<month>04</month>
<year>2024</year>
</date>
</history>
<permissions>
<copyright-statement>Copyright &#xa9; 2024 Wang, Wang, Peng, Fei and Wei</copyright-statement>
<copyright-year>2024</copyright-year>
<copyright-holder>Wang, Wang, Peng, Fei and Wei</copyright-holder>
<license xlink:href="http://creativecommons.org/licenses/by/4.0/">
<p>This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.</p>
</license>
</permissions>
<related-article id="RA1" related-article-type="commentary-article" xlink:href="https://www.frontiersin.org/research-topics/53844" ext-link-type="uri">Editorial on the Research Topic <article-title>Molecular mechanisms of fruit quality formation in fruit trees</article-title>
</related-article>
<kwd-group>
<kwd>molecular mechanisms</kwd>
<kwd>fruit quality</kwd>
<kwd>fruit trees</kwd>
<kwd>transcriptomic and metabolomic analysis</kwd>
<kwd>fruit development and ripening</kwd>
</kwd-group>
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<fig-count count="0"/>
<table-count count="0"/>
<equation-count count="0"/>
<ref-count count="6"/>
<page-count count="3"/>
<word-count count="1091"/>
</counts>
<custom-meta-wrap>
<custom-meta>
<meta-name>section-in-acceptance</meta-name>
<meta-value>Functional and Applied Plant Genomics</meta-value>
</custom-meta>
</custom-meta-wrap>
</article-meta>
</front>
<body>
<p>Fruits, abundant in various nutrients, play a crucial role in the modern diet and offer numerous health benefits to humans (<xref ref-type="bibr" rid="B6">Yisimayili and Chao, 2022</xref>). With the world population booming, there&#x2019;s a heightened need for fruit quality to meet the escalating global demand. This is because fruit quality largely determines its acceptance and preference among consumers, market share, and economic value. Fruit quality includes both interior and exterior characteristics, including color, sheen, size, texture, flavor, taste, and content of common and/or specific nutrients (<xref ref-type="bibr" rid="B1">Buthelezi et&#xa0;al., 2021</xref>; <xref ref-type="bibr" rid="B4">Muhammad et&#xa0;al., 2023</xref>). While fruit quality as aforementioned is primarily determined by its genetic composite, it can also be influenced by environmental factors such as temperature, light, humidity, cultivation systems, and certain stresses. As a result, fruit quality is complex trait that has attracted considerable research attention.</p>
<p>Unlike other horticultural crops such as vegetables and flowers, fruit trees generally undergo a lengthy juvenile phase, which present challenges for fruit quality studies. These challenges include, but are not limited to, the extended time required for trees to mature and produce the desired quality of fruit, the complexity involved in conducting experimental designs and assessing fruit quality, and the complications in breeding programs and genetic studies aimed at improving fruit quality. However, with the application and advancement of omics and gene editing technologies, we are unraveling elucidating the molecular mechanisms underlying fruit development and ripening in model plants (<xref ref-type="bibr" rid="B5">Sabbadini et&#xa0;al., 2021</xref>; <xref ref-type="bibr" rid="B2">Li et&#xa0;al., 2022</xref>; <xref ref-type="bibr" rid="B3">Liu et&#xa0;al., 2022</xref>). Yet, there remains a pressing need for a comprehensive understanding of the physio-ecological processes and molecular mechanisms involved in fruit quality formation, especially in fruit trees. Further research advances in this area will greatly facilitate the cultivation of high-quality, nutrient-rich germplasms for developing fruit trees.</p>
<p>The current Research Topic encompassed a total of eight academic articles, focusing on five different fruits: jujube, sour jujube, apricot, loquat, and others. Among these, four articles employed integrated transcriptomic and metabolomic analyses to elucidate the mechanisms associated with fruit quality. One article, compiling and scrutinizing research data from the past decade, revealed that antioxidant activity has the highest co-occurrence with other indicators of fruit quality. Particularly noteworthy is its correlation with anthocyanins, phenolic compounds, sugars, and fruit hardness.</p>
<p>The study conducted by <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.3389/fpls.2023.1294989">Ni et&#xa0;al.</ext-link> encompassed a comprehensive analysis of fruit quality-related literature spanning from January 2013 to June 2023, employing bibliometric analysis and data mining techniques. The primary objective was to provide guidance for both fundamental and practical research endeavors in the realm of fruit quality. Their research identified tomatoes as the most extensively studied fruit, particularly focusing on topics such as photosynthesis, fruit development, and molecular breeding. The prevailing research direction predominantly centered on exploring the resistance and storage attributes of fruits. A notable finding was the significant role of antioxidant activity as a key determinant of fruit quality, exhibiting strong correlations with other quality-related factors such as anthocyanins, phenolic substances, sugars, and fruit firmness. In another study by <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.3389/fpls.2023.1170723">Cao et&#xa0;al.</ext-link>, the research delved into the biosynthesis of triacylglycerols, revealing insights into the genetic mechanisms. They identified 280 genes encoding seven distinct classes of enzymes involved in this process. showed that 280 genes encoding seven distinct classes of enzymes are involved in the biosynthesis of triacylglycerols. Among them, functional redundancy was observed in some duplicated genes, likely stemming from the large-scale duplication events. Furthermore, the absence of the PDCT pathway in <italic>Vernicia fordii</italic> and <italic>Xanthoceras sorbifolium</italic> was highlighted, setting a groundwork for further studying the functions of the key genes in triacylglycerols-biosynthesis.</p>
<p>The study conducted by <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.3389/fpls.2023.1285456">Su et&#xa0;al.</ext-link> on anthocyanin and carotenoid accumulation of loquat fruits, which was analyzed through metabolome and transcriptome analyses, revealed that the orange color of &#x2018;Jiefangzhong&#x2019; (JFZ) fruit was primarily resulting from carotenoids, while the red color of wild <italic>Eriobotrya henryi</italic> (EH) was attributed to cyanidin-3-O-galactoside and pelargonidin-3-O-galactoside. Furthermore, the variations in transcript levels of <italic>F3H</italic>, <italic>F3&#x2019;H</italic>, <italic>ANS</italic>, <italic>CHS</italic> and <italic>CHI</italic> contributed significantly to the color distinctions observed between t these fruits. Additionally, two other studies conducted by <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.3389/fpls.2023.1210309">Chen et&#xa0;al.</ext-link> and <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.3389/fpls.2023.1187551">Han et&#xa0;al.</ext-link> focused on flavonoid synthesis in apricot fruits across different cultivars, by transcriptome and metabolome analyses. In both studies, many differentially expressed genes (DEGs) and different types of flavonols were identified. <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.3389/fpls.2023.1210309">Chen et&#xa0;al.</ext-link> highlighted key DEGs related to flavonoids biosynthesis along with identification of three transcription factor genes (2 <italic>bHLHs</italic> and 1 <italic>MYB</italic>) On the other hand, <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.3389/fpls.2023.1187551">Han et&#xa0;al.</ext-link> identified two transcription factor genes (<italic>PARG27864</italic> and P<italic>ARG10875</italic>) associated with <italic>PARG09190</italic> and <italic>PARG15135</italic>. These findings shed new light on the molecular mechanisms governing flavonoid biosynthesis in apricot fruits, providing valuable insights into this aspect of fruit quality.</p>
<p>The other three studies delved into flavonoid biosynthesis, sugar-acid fractions, and alkaloid metabolism in Chinese jujube fruits. In the study by <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.3389/fpls.2023.1171288">Muhammad et&#xa0;al.</ext-link>, an analysis of the transcription factor MYB family in <italic>Ziziphus. mauritiana</italic> and <italic>Ziziphus jujuba</italic> revealed that the transient expression of <italic>ZjMYB44</italic> in jujube fruits resulted in increased flavonoid content. Yang et&#xa0;al. conducted a study involving a F<sub>1</sub> population (179 hybrid progeny) of <italic>Ziziphus jujuba</italic> Mill. &#x2018;JMS2&#x2019; and (<italic>Z. acido jujuba</italic>) &#x2018;Xing16&#x2019;, where the analysis of this population identified three additive-dominant major gene and polygenes one associated with glucose synthesis, and two involved in malic acid synthesis. <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.3389/fpls.2023.1267758">Xue et&#xa0;al.</ext-link> identified 44 differential alkaloid metabolites (DAMs) that were highly and specifically accumulated in sour jujube compared to Chinese jujube. Additionally, transcriptome analysis led to the identification of 259 DEGs, Through the regulatory networks of DAMs and DEGs,11 candidate genes involved alkaloid synthesis and metabolism were identified. These studies collectively offer new insights into the molecular mechanisms shaping jujube fruit quality formation.</p>
<p>In summary, this topic underscores the recent impact of advanced genomic tools and technologies on investigating the mechanisms underlying fruit quality formation. Increased utilization multi-omics approaches and advanced bioinformatics tools for gene family identification advanced our understanding in this fields, offering strong theoretical support for accelerating fruit tree breeding and meeting the rising demand for high-quality fruits.</p>
<p>Collectively, these studies have made significant contribution to the comprehension of secondary metabolite biosynthesis in fruits, laying a solid foundation for further research and potential applications in enhancing fruit quality through genetic improvement and breeding programs.</p>
<sec id="s1" sec-type="author-contributions">
<title>Author contributions</title>
<p>LHW: Funding acquisition, Writing &#x2013; original draft, Writing &#x2013; review &amp; editing. LXW: Writing &#x2013; original draft, Writing &#x2013; review &amp; editing. ZP: Writing &#x2013; original draft, Writing &#x2013; review &amp; editing. XF: Writing &#x2013; original draft, Writing &#x2013; review &amp; editing. HW: Writing &#x2013; original draft, Writing &#x2013; review &amp; editing.</p>
</sec>
</body>
<back>
<sec id="s2" sec-type="funding-information">
<title>Funding</title>
<p>The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This work was supported by Natural Science Foundation of Hebei, China (C2022402021), the Science and Technology Research Project of University in Hebei Province (QN2020205), Science, Technology Research and Development Plan Project of Handan (19422011008&#x2013;49) and National Natural Science Foundation of China (32201599).</p>
</sec>
<sec id="s3" sec-type="COI-statement">
<title>Conflict of interest</title>
<p>The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.</p>
<p>The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision.</p>
</sec>
<sec id="s4" sec-type="disclaimer">
<title>Publisher&#x2019;s note</title>
<p>All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.</p>
</sec>
<ref-list>
<title>References</title>
<ref id="B1">
<citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname>Buthelezi</surname> <given-names>N. M. D.</given-names>
</name>
<name>
<surname>Mafeo</surname> <given-names>T. P.</given-names>
</name>
<name>
<surname>Mathaba</surname> <given-names>N.</given-names>
</name>
</person-group> (<year>2021</year>). <article-title>Preharvest bagging as an alternative technique for enhancing fruit quality: A review</article-title>. <source>HortTechnology</source> <volume>31</volume>, <fpage>4</fpage>&#x2013;<lpage>13</lpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.21273/HORTTECH04658&#x2013;20</pub-id>
</citation>
</ref>
<ref id="B2">
<citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname>Li</surname> <given-names>J.</given-names>
</name>
<name>
<surname>Yan</surname> <given-names>G.</given-names>
</name>
<name>
<surname>Zhang</surname> <given-names>X.</given-names>
</name>
<name>
<surname>Hua</surname> <given-names>X.</given-names>
</name>
</person-group> (<year>2022</year>). <article-title>Research progress and trends in metabolomics of fruit trees</article-title>. <source>Front. Plant Sci.</source> <volume>13</volume>. doi:&#xa0;<pub-id pub-id-type="doi">10.3389/fpls.2022.881856</pub-id>
</citation>
</ref>
<ref id="B3">
<citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname>Liu</surname> <given-names>W.</given-names>
</name>
<name>
<surname>Chen</surname> <given-names>Z.</given-names>
</name>
<name>
<surname>Jiang</surname> <given-names>S.</given-names>
</name>
<name>
<surname>Wang</surname> <given-names>Y.</given-names>
</name>
<name>
<surname>Fang</surname> <given-names>H.</given-names>
</name>
<name>
<surname>Zhang</surname> <given-names>Z.</given-names>
</name>
<etal/>
</person-group>. (<year>2022</year>). <article-title>Research progress on genetic basis of fruit quality traits in apple (<italic>Malus&#xd7; domestica</italic>)</article-title>. <source>Front. Plant Sci.</source> <volume>13</volume>. doi:&#xa0;<pub-id pub-id-type="doi">10.3389/fpls.2022.918202</pub-id>
</citation>
</ref>
<ref id="B4">
<citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname>Muhammad</surname> <given-names>N.</given-names>
</name>
<name>
<surname>Luo</surname> <given-names>Z.</given-names>
</name>
<name>
<surname>Yang</surname> <given-names>M.</given-names>
</name>
<name>
<surname>Liu</surname> <given-names>Z.</given-names>
</name>
<name>
<surname>Liu</surname> <given-names>M.</given-names>
</name>
</person-group> (<year>2023</year>). <article-title>The underlying molecular mechanisms of external factors influencing fruit coloration in fruit trees</article-title>. <source>Scientia Hortic.</source> <volume>309</volume>, <elocation-id>111615</elocation-id>. doi:&#xa0;<pub-id pub-id-type="doi">10.1016/j.scienta.2022.111615</pub-id>
</citation>
</ref>
<ref id="B5">
<citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname>Sabbadini</surname> <given-names>S.</given-names>
</name>
<name>
<surname>Capocasa</surname> <given-names>F.</given-names>
</name>
<name>
<surname>Battino</surname> <given-names>M.</given-names>
</name>
<name>
<surname>Mazzoni</surname> <given-names>L.</given-names>
</name>
<name>
<surname>Mezzetti</surname> <given-names>B.</given-names>
</name>
</person-group> (<year>2021</year>). <article-title>Improved nutritional quality in fruit tree species through traditional and biotechnological approaches</article-title>. <source>Trends Food Sci. Technol.</source> <volume>117</volume>, <fpage>125</fpage>&#x2013;<lpage>138</lpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1016/j.tifs.2021.01.083</pub-id>
</citation>
</ref>
<ref id="B6">
<citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname>Yisimayili</surname> <given-names>Z.</given-names>
</name>
<name>
<surname>Chao</surname> <given-names>Z.</given-names>
</name>
</person-group> (<year>2022</year>). <article-title>A review on phytochemicals, metabolic profiles and pharmacokinetics studies of the different parts (juice, seeds, peel, flowers, leaves and bark) of pomegranate (<italic>Punica granatum</italic> L.)</article-title>. <source>Food Chem.</source> <volume>395</volume>, <elocation-id>133600</elocation-id>. doi:&#xa0;<pub-id pub-id-type="doi">10.1016/j.foodchem.2022.133600</pub-id>
</citation>
</ref>
</ref-list>
</back>
</article>