Tomato GOLDEN2-LIKE Transcription Factors Reveal Molecular Gradients That Function during Fruit Development and Ripening
Tomato GOLDEN2-LIKE Transcription Factors Reveal Molecular Gradients That Function during Fruit Development and Ripening
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DOI：
10.1105/tpc.113.118794
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发表时间：
2014-02-01
期刊：
影响因子：
11.6
通讯作者：
Giovannoni, James J.
中科院分区：
文献类型：
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作者：
Nguyen, Cuong V.;Vrebalov, Julia T.;Giovannoni, James J.
果实成熟是使肉质果实组织对种子传播生物具有吸引力和美味的变化的总和。例如，糖含量受未成熟果实质体数量和光合活性的影响，随后受成熟过程中淀粉和糖分解代谢的影响。番茄果实是光合作用的汇，但未成熟的青果对最终在成熟果实中积累的糖有显著贡献。质体数量和叶绿素含量受多种环境和遗传因素的影响，并与光合作用和光合产物积累呈正相关。GOLDEN2-LIKE转录因子调节质体和叶绿素水平。番茄（Solanum lycopersicum），像大多数植物一样，含有两种glk（即GLK1和GLK2/UNIFORM）。突变和转基因分析表明，这些基因编码功能相似的肽，尽管差异表达使GLK1在叶片中更重要，而GLK2在果实中占主导地位。GLK2表达的纬度梯度影响野生型青熟果实典型的不均匀颜色。转录组分析揭示了整个发育过程中更广泛的果实基因表达梯度。这种梯度影响了质体发育以外的一般成熟活动，与番茄和许多肉质水果中容易观察到但研究较少的成熟梯度一致。
Fruit ripening is the summation of changes rendering fleshy fruit tissues attractive and palatable to seed dispersing organisms. For example, sugar content is influenced by plastid numbers and photosynthetic activity in unripe fruit and later by starch and sugar catabolism during ripening. Tomato fruit are sinks of photosynthate, yet unripe green fruit contribute significantly to the sugars that ultimately accumulate in the ripe fruit. Plastid numbers and chlorophyll content are influenced by numerous environmental and genetic factors and are positively correlated with photosynthesis and photosynthate accumulation. GOLDEN2-LIKE (GLK) transcription factors regulate plastid and chlorophyll levels. Tomato (Solanum lycopersicum), like most plants, contains two GLKs (i.e., GLK1 and GLK2/UNIFORM). Mutant and transgene analysis demonstrated that these genes encode functionally similar peptides, though differential expression renders GLK1 more important in leaves, while GLK2 is predominant in fruit. A latitudinal gradient of GLK2 expression influences the typical uneven coloration of green and ripe wild-type fruit. Transcriptome profiling revealed a broader fruit gene expression gradient throughout development. The gradient influenced general ripening activities beyond plastid development and was consistent with the easily observed yet poorly studied ripening gradient present in tomato and many fleshy fruits.