Fig 1.
Accumulation of ABA and ABA-GE content in different types of watermelon fruits.
ABA and ABA-GE content in center flesh (A), mesocarp (B), seed (C), placenta (D) and whole fruit (E) during 97103, PI179878 and PI296341-FR watermelon fruit development and ripening. (F) Pictures of 97103, PI179878 and PI296341-FR watermelon fruits at the ripening stage, respectively at 34, 34 and 50 DAP. Sampled tissues are indicated in blue.
Fig 2.
Effects of ABA on watermelon fruit ripening.
(A) ABA and SSC content in six cultivated, thirteen semi-wild, six wild and six ancestral watermelon accessions at the ripening stage. Values are means of three independent replicates. Changes of fruit color (B), center flesh SSC (C) and firmness (D) in cultivated watermelon 97103 after ABA and NDGA treatment. Error bars on each point indicate ±SE from three independent replicates. Pairwise comparisons between the treatments were done with ANOVA and means were separated with Fisher’s test α< 0.05.
Fig 3.
Expressions of key ABA metabolism genes in center flesh, mesocarp and placenta.
Expression levels of Cla009779 (ClNCED), Cla005404 (ClNCED), Cla005457 (ClCYP707A), Cla020673 (ClCYP707A) and Cla016011 (ClCYP707A) in the center flesh (A, B, C, D, E), mesocarp (F, G, H, I, J) and placenta (K, L, M, N, O) of 97103, PI179878 and PI296341-FR during watermelon fruit development and ripening. Standard errors are indicated. * indicates expression values that are significantly different at the 0.01 level compared to PI196341-FR at each developmental stage.
Fig 4.
Expression patterns of ABA pathway genes.
Expression profiles of key ABA metabolism and core ABA signal transduction genes across different watermelon developmental stages in 97103 and PI296341-FR center flesh. The scale representing the relative signal intensity values is shown above. DAP: Days After Pollination.
Fig 5.
Genetic variations of Cla020673 (CYP707A) and Cla020180 (SnRK2) in the putative promoter regions of different watermelon accessions.
The minus numbers represent the SNP position up the start codon and numbers above stand for the correlation of the corresponding SNP with SSC. The SNPs with asterisk and inverted triangle are the ones that have higher correlation values.