title: Tomato facultative parthenocarpy results from SlAGAMOUS-LIKE 6 loss of function.
abstract: The extreme sensitivity of the microsporogenesis process to moderately high or low temperatures is a major hindrance for tomato (Solanum lycopersicum) sexual reproduction and hence year-round cropping. Consequently, breeding for parthenocarpy, namely, fertilization-independent fruit set, is considered a valuable goal especially for maintaining sustainable agriculture in the face of global warming. A mutant capable of setting high-quality seedless (parthenocarpic) fruit was found following a screen of EMS-mutagenized tomato population for yielding under heat stress. Next-generation sequencing followed by marker-assisted mapping and CRISPR/Cas9 gene knockout confirmed that a mutation in SlAGAMOUS-LIKE 6 (SlAGL6) was responsible for the parthenocarpic phenotype. The mutant is capable of fruit production under heat stress conditions that severely hamper fertilization-dependent fruit set. Different from other tomato recessive monogenic mutants for parthenocarpy, Slagl6 mutations impose no homeotic changes, the seedless fruits are of normal weight and shape, pollen viability is unaffected, and sexual reproduction capacity is maintained, thus making Slagl6 an attractive gene for facultative parthenocarpy. The characteristics of the analysed mutant combined with the gene's mode of expression imply SlAGL6 as a key regulator of the transition between the state of 'ovary arrest' imposed towards anthesis and the fertilization-triggered fruit set.
authors.affiliation: The Institute of Plant Sciences, The Volcani Center, Agricultural Research Organization, Rishon LeZion, Israel.
authors.forename: Chen
authors.initials: C
authors.lastname: Klap
authors.affiliation: The Institute of Plant Sciences, The Volcani Center, Agricultural Research Organization, Rishon LeZion, Israel.
authors.forename: Ester
authors.initials: E
authors.lastname: Yeshayahou
authors.affiliation: Institut für Biologie I, RWTH Aachen, Aachen, Germany.
authors.forename: Anthony M
authors.initials: AM
authors.lastname: Bolger
authors.affiliation: The Institute of Plant Sciences, The Volcani Center, Agricultural Research Organization, Rishon LeZion, Israel.
authors.forename: Tzahi
authors.initials: T
authors.lastname: Arazi
authors.affiliation: The Institute of Plant Sciences, The Volcani Center, Agricultural Research Organization, Rishon LeZion, Israel.
authors.forename: Suresh K
authors.initials: SK
authors.lastname: Gupta
authors.affiliation: The Institute of Plant Sciences, The Volcani Center, Agricultural Research Organization, Rishon LeZion, Israel.
authors.forename: Sara
authors.initials: S
authors.lastname: Shabtai
authors.affiliation: Institut für Biologie I, RWTH Aachen, Aachen, Germany.|Institut für Bio-und Geowissenschaften 2 (IBG-2) Plant Sciences, Forschungszentrum Jülich, Jülich, Germany.
authors.forename: Björn
authors.initials: B
authors.lastname: Usadel
authors.affiliation: The Institute of Plant Sciences, The Volcani Center, Agricultural Research Organization, Rishon LeZion, Israel.
authors.forename: Yehiam
authors.initials: Y
authors.lastname: Salts
authors.affiliation: The Institute of Plant Sciences, The Volcani Center, Agricultural Research Organization, Rishon LeZion, Israel.
authors.forename: Rivka
authors.initials: R
authors.lastname: Barg
mesh_terms: D064113:CRISPR-Cas Systems; D005638:Fruit / Q000235:genetics* / Q000254:growth & development; D018506:Gene Expression Regulation, Plant; D018869:Heat-Shock Response / Q000235:genetics; D018551:Solanum lycopersicum / Q000235:genetics* / Q000502:physiology; D009154:Mutation; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified; D012639:Seeds / Q000235:genetics
chemical_list: D010940:Plant Proteins
keywords: CRISPR/Cas9; SlAGL6; Solyc01g093960; fruit set; ovary arrest; tomato fruit size