A Non-Climacteric Fruit Gene <i>CaMADS-RIN</i> Regulates Fruit Ripening and Ethylene Biosynthesis in Climacteric Fruit

<div><p>MADS-box genes have been reported to play a major role in the molecular circuit of developmental regulation. Especially, <i>SEPALLATA</i> (<i>SEP</i>) group genes play a central role in the developmental regulation of ripening in both climacteric and non-climacteric fruits. However, the mechanisms underlying the regulation of <i>SEP</i> genes to non-climacteric fruits ripening are still unclear. Here a <i>SEP</i> gene of pepper, <i>CaMADS-RIN</i>, has been cloned and exhibited elevated expression at the onset of ripening of pepper. To further explore the function of <i>CaMADS-RIN</i>, an overexpressed construct was created and transformed into <i>ripening inhibitor</i> (<i>rin</i>) mutant tomato plants. Broad ripening phenotypes were observed in <i>CaMADS-RIN</i> overexpressed <i>rin</i> fruits. The accumulation of carotenoid and expression of <i>PDS</i> and <i>ZDS</i> were enhanced in overexpressed fruits compared with <i>rin</i> mutant. The transcripts of cell wall metabolism genes (<i>PG</i>, <i>EXP1</i> and <i>TBG4</i>) and lipoxygenase genes (<i>TomloxB</i> and <i>TomloxC</i>) accumulated more abundant compared to <i>rin</i> mutant. Besides, both ethylene-dependent genes including <i>ACS2</i>, <i>ACO1</i>, <i>E4</i> and <i>E8</i> and ethylene-independent genes such as <i>HDC</i> and <i>Nor</i> were also up-regulated in transgenic fruits at different levels. Moreover, transgenic fruits showed approximately 1–3 times increase in ethylene production compared with <i>rin</i> mutant fruits. Yeast two-hybrid screen results indicated that CaMADS-RIN could interact with TAGL1, FUL1 and itself respectively as SlMADS-RIN did in vitro. These results suggest that <i>CaMADS-RIN</i> affects fruit ripening of tomato both in ethylene-dependent and ethylene-independent aspects, which will provide a set of significant data to explore the role of <i>SEP</i> genes in ripening of non-climacteric fruits.</p></div

Anthocyanin Accumulation and Transcriptional Regulation of Anthocyanin Biosynthesis in Purple Bok Choy (Brassica rapa var. <i>chinensis</i>)

Bok choy (Brassica rapa var. chinensis) is an important dietary vegetable cultivated and consumed worldwide for its edible leaves. The purple cultivars rich in health-promoting anthocyanins are usually more eye-catching and valuable. Fifteen kinds of anthocyanins were separated and identified from a purple bok choy cultivar (Zi He) by high-performance liquid chromatography–electrospray ionization tandem mass spectrometry. To investigate the molecular mechanisms underlying anthocyanin accumulation in bok choy, the expression profiles of anthocyanin biosynthetic and regulatory genes were analyzed in seedlings and leaves of the purple cultivar and the green cultivar (Su Zhouqing). Compared with the other tissues, BrTT8 and most of the anthocyanin biosynthetic genes were significantly up-regulated in the leaves and light-grown seedlings of Zi He. The results that heterologous expression of BrTT8 promotes the transcription of partial anthocyanin biosynthetic genes in regeneration shoots of tomato indicate that BrTT8 plays an important role in the regulation of anthocyanin biosynthesis

Additional file 1 of Transcriptomics reveals the molecular mechanisms of flesh colour differences in eggplant (Solanum melongena)

Additional file 1: Figure S1. qRT-PCR results of the selected genes and correlation between transcriptome data and real time PCR results

Expression profile of <i>CaMADS-RIN</i> in tissues of pepper.

<p>The expression of <i>CaMADS-RIN</i> in Rt, roots; St, stems; Le, leaves; Fl, flowers; Sf, fruits of 1 cm; Bf, fruits of 6 cm; Of, orange fruits; Rf, red fruits. Expression was determined by Q-RT-PCR as relative quantification. Results are of a representative experiment, and are an average of three repetitions ±SD.</p

Expression of ethylene-independent genes in overexpressed lines, <i>rin</i> mutants and wild type fruits.

<p>(a). Expression of a histidine metabolism gene <i>HDC</i> in overexpressed lines, <i>rin</i> mutants and wild type fruits. (b). Expression of <i>Nor</i> in overexpressed lines, <i>rin</i> mutants and wild type fruits. RNAs were extracted for qPCR assay from B, B+4 and B+7 fruits of overexpressed lines, <i>rin</i> mutant and wild type. Three replications for each sample were performed.</p

Cell wall metabolism genes in <i>CaMADS-RIN</i> overexpressed <i>rin</i> and control fruits.

<p>(a). Expression of <i>PG</i> in B, B+4 and B+7 fruits of transgenic lines (ov-01 and ov-03), <i>rin</i> and wild type. (b). Expression of <i>TBG4</i> in B, B+4 and B+7 fruits of transgenic lines (ov-01 and ov-03), <i>rin</i> and wild type. (c). Expression of <i>EXP1</i> in B, B+4 and B+7 fruits of transgenic lines (ov-01 and ov-03), <i>rin</i> and wild type.</p

Additional file 4 of Transcriptomics reveals the molecular mechanisms of flesh colour differences in eggplant (Solanum melongena)

Additional file 4: Table S3. Primers used in the q-PCR analysis

DataSheet_1_Comparative transcriptome analysis reveals the involvement of an MYB transcriptional activator, SmMYB108, in anther dehiscence in eggplant.pdf

Male sterility is a highly attractive agronomic trait as it effectively prevents self-fertilization and facilitates the production of high-quality hybrid seeds in plants. Timely release of mature pollen following anther dehiscence is essential for stamen development in flowering plants. Although several theories have been proposed regarding this, the specific mechanism of anther development in eggplant remains elusive. In this study, we selected an R2R3-MYB transcription factor gene, SmMYB108, that encodes a protein localized primarily in the nucleus by comparing the transcriptomics of different floral bud developmental stages of the eggplant fertile line, F142. Quantitative reverse transcription polymerase chain reaction revealed that SmMYB108 was preferentially expressed in flowers, and its expression increased significantly on the day of flowering. Overexpression of SmMYB108 in tobacco caused anther dehiscence. In addition, we found that SmMYB108 primarily functions as a transcriptional activator via C-terminal activation (amino acid 262–317). Yeast one-hybrid and dual-luciferase reporter assays revealed that genes (SmMYB21, SmARF6, and SmARF8) related to anther development targeted the SmMYB108 promoter. Overall, our results provide insights into the molecular mechanisms involved in the regulation of anther development by SmMYB108.</p

Additional file 3 of Transcriptomics reveals the molecular mechanisms of flesh colour differences in eggplant (Solanum melongena)

Additional file 3: Table S2. DEGs between NC7 and BL

Additional file 2 of Transcriptomics reveals the molecular mechanisms of flesh colour differences in eggplant (Solanum melongena)

Additional file 2: Table S1. Data qualities statistics of RNA-seq in eggplant flesh