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Fruit color is an important trait influencing the commercial value of eggplant fruits. Three dominant genes (D , P and Y) cooperatively control the anthocyanin coloration in eggplant fruits, but none has been mapped. In this study, two white-fruit accessions (19 141 and 19 147) and their F2 progeny, with 9:7 segregation ratio of anthocyanin pigmented versus non-pigmented fruits, were used for mapping the D and P genes. A high-density genetic map was constructed with 5270 SNPs spanning 1997.98 cM. Three QTLs were identified, including two genes on chromosome 8 and one on chromosome 10. Gene expression analyses suggested that the SmANS on chromosome 8 and SmMYB1 on chromosome 10 were the putative candidate genes for P and D , respectively. We further identified (1) a SNP leading to a premature stop codon within the conserved PLN03176 domain of SmANS in 19 141, (2) a G base InDel in the promoter region leading to an additional cis -regulatory element and (3) a 6-bp InDel within the R2-MYB DNA binding domain of SmMYB1 , in 19 147. Subsequently, these three variations were validated by PARMS technology as related to phenotypes in the F2 population. Moreover, silencing of SmANS or SmMYB1 in the purple red fruits of F1 (E3316) led to inhibition of anthocyanin biosynthesis in the peels. Conversely, overexpression of SmANS or SmMYB1 restored anthocyanin biosynthesis in the calli of 19 141 and 19 147 respectively. Our findings demonstrated the epistatic interactions underlying the white color of eggplant fruits, which can be potentially applied to breeding of eggplant fruit peel color. [ABSTRACT FROM AUTHOR]

Resistant crop cultivars can recruit beneficial rhizobacteria to resist disease. However, whether this recruitment is regulated by quantitative trait loci (QTL) is unclear. The role of QTL in recruiting specific bacteria against bacterial wilt (BW) is an important question of practical significance to disease management. Here, to identify QTL controlling BW resistance, Super-BSA was performed in F 2 plants derived from resistant eggplant cultivar R06112 × susceptible cultivar S55193. The QTL was narrowed down through BC 1 F 1 -BC 3 F 1 individuals by wilting symptoms and KASP markers. Rhizosphere bacterial composition of R06112, S55193, and resistant individuals EB158 (with the QTL) and susceptible individuals EB327 (without QTL) from BC 2 F 1 generation were assessed by Illumina sequencing-based analysis, and the activation of plant immunity by the bacterial isolates was analyzed. Evidence showed that BW-resistant is controlled by one QTL located at the 270 kb region on chromosome 10, namely EBWR10 , and nsLTPs as candidate genes confirmed by RNA-Seq. EBWR10 has a significant effect on rhizobacteria composition and significantly recruits Bacillus . pp. A SynCom of three isolated Bacillus . pp trains significantly reduced the disease incidence, changed activities of CAT, PPO, and PAL and concentration of NO, H 2 O 2 , and O 2 - , activated SA and JA signaling-dependent ISR, and displayed immune activation against Ralstonia solanacearum in eggplant. Our findings demonstrate for the first time that the QTL can recruit beneficial rhizobacteria, which jointly promote the suppression of BW. This method charts a path to develop the QTL in resistant cultivar-driven probiotics to ameliorate plant diseases., Competing Interests: The authors declare that there are no conflicts of interest., (© The Author(s) 2024. Published by Oxford University Press on behalf of Nanjing Agricultural University.)

The phytohormone ethylene is well known for its important role in the ripening of climacteric fruit, such as tomato ( Solanum lycopersicum ). However, the role and mode of action of other plant hormones in climacteric fruit ripening regulation are not fully understood. Here, we showed that exogenous GA treatment or increasing endogenous gibberellin content by overexpressing the gibberellin synthesis gene SlGA3ox2 specifically in fruit tissues delayed tomato fruit ripening, whereas treatment with the GA biosynthesis inhibitor paclobutrazol (PAC) accelerated fruit ripening. Moreover, exogenous ethylene treatment cannot completely reverse the delayed fruit ripening phenotype. Furthermore, exogenous GA treatment of ethylene signalling mutant Never ripe ( Nr ) or SlEBF3 -overexpressing lines still delayed fruit ripening, suggesting that GA involved in fruit ripening partially depends on ethylene. Transcriptome profiling showed that gibberellin affect the ripening of fruits by modulating the metabolism and signal transduction of multiple plant hormones, such as auxin and abscisic acid, in addition to ethylene. Overall, the results of this study provide new insight into the regulation of gibberellin in fruit ripening through mediating multiple hormone signals., Competing Interests: The authors declare no conflict of interest., (© The Author(s) 2024. Published by Oxford University Press on behalf of Nanjing Agricultural University.)