Genetic and physiological characterization of three natural allelic variations affecting the organogenic capacity in tomato (Solanum lycopersicum cv. Micro-Tom)

Author(s)

Pinto, Masia de Siqueira ; Abeyratne, Chanaka Roshan ; Benedito, Vagner Augusto ; Peres, Lazaro E. P.

• Document type: Journal article
• Source: PLANT CELL TISSUE AND ORGAN CULTURE; v. 129, n. 1, p. 89-103, APR 2017.
• Web of Science Citations: 3

Abstract

The study of allelic variations affecting organogenic capacity is not only relevant for manipulating plant traits but also to understand the fundamental mechanisms involved in plant development. Here, we report the characterization of three tomato (Solanum lycopersicum) loci (RG3C, RG7H and RG8F) whose alleles from its wild relative Solanum pennellii enhance in vitro shoot and root regeneration. S. pennellii alleles were introgressed into tomato cv. Micro-Tom (MT), creating near-isogenic lines. We evaluated the time taken for shoot induction and acquisition of competence by quantifying organogenesis after transferring explants, respectively, from the shoot-inducing medium (SIM) to the basal medium (BM) and from rootinducing medium (RIM) to the SIM. Concomitantly, we monitored the expression of key developmental genes. MTRg3C and MT-Rg7H started shoot induction, respectively, at 48 and 24 h earlier than MT and MT-Rg8F, while MTRg3C and MT-Rg8F acquired competence 24 h before MT. The impact of MT-Rg3C and MT-Rg8F in the acquisition of competence to assume different fates is consistent with their effect enhancing both shoot and root regeneration. MT-Rg7H seems to affect shoot induction specifically, which is in agreement with the enhanced expression of the shoot-related genes WUSCHEL and SHOOT MERIS-TEMLESS. Phenotypic characterization of greenhouse-grown plants showed that Rg3C has increased branching when compared to MT. Conversely, the normal branching observed in MT-Rg7H and MT-Rg8F indicates that adven-titious in vitro shoot formation and ex vitro axillary bud formation/outgrowth are induced by different genetic path-ways. These natural variations are thus useful for breeding highly regenerating varieties without undesirable effects on plant architecture. (AU)

• FAPESP's process: 14/17553-5 - Analysis of goblet and LeGAI spatial-temporal expression in tomato introgression lines with high regeneration capacity
• Grantee: Maísa de Siqueira Pinto
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• FAPESP's process: 12/24714-0 - Characterization of genetic variation in tomato affecting the competence to assume different developmental fates
• Grantee: Maísa de Siqueira Pinto
• Support Opportunities: Scholarships in Brazil - Doctorate