Approaching the genetic dissection of indirect adventitious organogenesis process in tomato explants

• Published in: Plant science (Limerick) 2021-01, Vol.302, p.110721-110721, Article 110721
• Main Authors: Sánchez-López, Jorge, Atarés, Alejandro, Jáquez-Gutiérrez, Marybel, Ortiz-Atienza, Ana, Capel, Carmen, Pineda, Benito, García-Sogo, Begoña, Yuste-Lisbona, Fernando J., Lozano, Rafael, Moreno, Vicente
• Format: Article
• Language: English
• Subjects: Adventitious organogenesis; Genes, Plant - genetics; Genes, Plant - physiology; Genetic Association Studies; Lycopersicon esculentum - genetics; Lycopersicon esculentum - physiology; Meristem - genetics; Meristem - physiology; Mutants; Plant Roots - physiology; Plant Shoots - physiology; Regeneration - genetics; Shoot-bud differentiation; SlMAPKKK17; Tomato
• ISSN: 0168-9452; 1873-2259
• DOI: 10.1016/j.plantsci.2020.110721

•Tomato mutants impaired in adventitious organogenesis were identified.•The genes altered in these mutants are key regulators of adventitious organogenesis.•Gene altered in tdc-1 plays a specific role in callus growth.•Gene altered in tds-1 plays a specific role in adventitious shoot development.•SlMAPKKK17 gene plays an important role in adventitious shoot-bud differentiation. The screening of 862 T-DNA lines was carried out to approach the genetic dissection of indirect adventitious organogenesis in tomato. Several mutants defective in different phases of adventitious organogenesis, namely callus growth (tdc-1), bud differentiation (tdb-1, -2, -3) and shoot-bud development (tds-1) were identified and characterized. The alteration of the TDC-1 gene blocked callus proliferation depending on the composition of growth regulators in the culture medium. Calli from tds-1 explants differentiated buds but did not develop normal shoots. Histological analysis showed that their abnormal development is due to failure in the organization of normal adventitious shoot meristems. Interestingly, tdc-1 and tds-1 mutant plants were indistinguishable from WT ones, indicating that the respective altered genes play specific roles in cell proliferation from explant cut zones (TDC-1 gene) or in the organization of adventitious shoot meristems (TDS-1 gene). Unlike the previous, plants of the three mutants defective in the differentiation of adventitious shoot-buds (tdb-1, -2, -3) showed multiple changes in vegetative and reproductive traits. Cosegregation analyses revealed the existence of an association between the phenotype of the tdb-3 mutant and a T-DNA insert, which led to the discovery that the SlMAPKKK17 gene is involved in the shoot-bud differentiation process.