Forward genetic studies reveal LsAPRR2 as a key gene in regulating the green color of pericarp in bottle gourd (Lagenaria siceraria)

Abstract

The fruit peel color is an important factor that affects its quality. However, genes involved in regulating pericarp color in bottle gourd (Lagenaria siceraria) have not been explored to date. Genetic analysis of color traits in bottle gourd peel through a genetic population of six generations demonstrated that the green color of peels is inherited as a single gene dominant trait. Combined phenotype-genotype analysis of recombinant plants using BSA-seq mapped the candidate gene to a 22.645 Kb interval at the head end of chromosome 1. We observed that the final interval contained only one gene, LsAPRR2 (HG_GLEAN_10010973). Sequence and spatiotemporal expression analyses of LsAPRR2 unraveled two nonsynonymous mutations (A→G) and (G→C) in the parental CDS sequences. Further, LsAPRR2 expression was higher in all green-skinned bottle gourds (H16) at various stages of fruit development than in white-skinned bottle gourds (H06). Cloning and sequence comparison of the two parental LsAPRR2 promoter regions indicated 11 bases insertion and 8 SNPs mutations in the region -991~-1033, upstream of the start codon in white bottle gourd. Proof of GUS reporting system, Genetic variation in this fragment significantly reduced the expression of LsAPRR2 in the pericarp of white bottle gourd. In addition, we developed a tightly linked (accuracy 93.88%) InDel marker for the promoter variant segment. Overall, the current study provides a theoretical basis for comprehensive elucidation of the regulatory mechanisms underlying the determination of bottle gourd pericarp color. This would further help in the directed molecular design breeding of bottle gourd pericarp.

Transcriptomics reveal useful resources for examining fruit development and variation in fruit size in Coccinia grandis

“…In the present study, ASIL 2 is downregulated in all the developmental stages of ANSa, and therefore, can be considered to have higher expression in ANKu, which suggests its role in elongation of fruit by some unknown mechanism. In addition to this, we also observed expression of gene SR43C which codes for chloroplast signal recognition particle and has role in chlorophyll synthesis and fruit quality ( Huo et al., 2023 ). Higher expression of SR43C in early stage of fruit development (5 DAA) in ANSa may imply a potential role of SR43C gene in determining fruit size through some unknown mechanisms.…”

Nutritional Variation on Sequentially Harvested Shoots and Fruits of Lagenaria siceraria Landraces

“…The ideal harvest stages for higher potassium in fruits were 7 (DSI, NqRC, and RSP) and 14 DAA (RSP), whereas for phosphorus, it was 7 (BG-24, BG-100/GC, and KRI) and 14 DAA (KSC). The potassium content in both shoots and fruits did not vary across all stages of growth in the majority of landraces, though some variations in phosphorus content were observed, possibly due to L. siceraria ’s ability to retain green-colored fruits from juvenile to mature [ 27 ]. The highest K and P content in landrace DSI, with solid, dark, green-colored fruits, and in landrace KSC, with solid, smooth pale-green fruits, as opposed to the lowest content in KRI, with green-colored fruits with cream warts, and NqSC, with solid, smooth, pale-green fruits across all growth phases ( Table 2 ), may have resulted from differences in saturation of the green pigment chlorophyll in the fruit pericarp [ 21 ].…”

“…Landraces DSI, NSRP, and ESC had the highest fruit neutral detergent fiber (NDF) content than other landraces at 7, 14, and 21 DAA, respectively (Table 4). 6.68 l-q 5.96 n-q 8.33 j-q BG-31 12.24 c-j 8.61 i-p 8.32 j-q BG-100/GC 7.90 j-q 13.83 b-g 18.87 a DSI 7.46 k-q 9.62 BG-19 27.94 g-q 23.30 l-q 24.09 k-q 36.42 b-i BG-24 20.57 n-q 23.40 l-q 22.89 m-q 37.00 b-h BG- 26 18.40 q 19.61 o-q 32.32 e-n 37.90 b-g BG- 27 18.90 pq 18.59 q 26.87 g-q 30.84 f-o BG-80 19.04 o-q 26.01 h-q 26.68 g-q 41.31 a-f BG-81 27.80 g-q 24.68 i-q 35.52 b-k 35.99 b-j BG-100/GC 28.12 g-q 23.84 k-q 32.26 e-n 43.03 a-e DSI 24.55 j-q 23.52 l-q 34.95 c-l 44.17 a-d ESC 20.77 m-q 22.02 m-q 29.49 f-q 37.06 b-h KRI 31.54 e-n 29.63 f-q 36.07 b-j 32.41 d-m KSC 25.05 i-q 21.36 m-q 30.62 29.54 m-q 31.80 i-q 42.73 c-j BG-24 30.47 k-q 33.28 g-q 30.71 k-q 49.16 a-e BG-26 25.37 q 27.48 o-q 38.38 e-p 44.95 b-g BG- 27 25.18 q 26.86 pq 35.53 f-q 39.73 c-n BG-80 25.15 q 32.94 h-q 35.23 f-q 50.99 a-d BG-81 34.80 f-q 32.45 h-q 41.85 c-k 43.80 c-h BG-100/GC 38.34 e-p 33.78 f-q 42.81 c-j 50.06 a-e DSI 31.37 j-q 29.87 l-q 44.14 4). Moreover, landraces BG-19, KRI, and NqSC had higher ADL content than all other landraces at 63 DAS.…”

Fine mapping of TFL, a major gene regulating fruit length in snake gourd (Trichosanthes anguina L)

“…The cDNA was synthesised using reverse transcriptase RT Master Mix (RR036A) following the manufacturer’s instructions (TaKaRa, Beijing, China). Each quantitative reverse transcription PCR (qRT-PCR) mixture was prepared and the quantitative fluorescence was analyzed according to the methods described by Huo et al [ 30 ]. Each quantitative reverse transcription PCR (qRT-PCR) mixture contained 2 µL cDNA, 0.8 µL forward and reverse primers, 10 µL TB Green Premix Ex TaqII, 0.4 µL ROX Reference Dye II, and 6 µL nuclease-free water.…”