High-Temperature-Induced Defects in Tomato (Solanum lycopersicum) Anther and Pollen Development Are Associated with Reduced Expression of B-Class Floral Patterning Genes

Abstract

Sexual reproduction is a critical process in the life-cycle of plants and very sensitive to environmental perturbations. To better understand the effect of high temperature on plant reproduction, we cultivated tomato (Solanum lycopersicum) plants in continuous mild heat. Under this condition we observed a simultaneous reduction in pollen viability and appearance of anthers with pistil-like structures, while in a more thermotolerant genotype, both traits were improved. Ectopic expression of two pistil-specific genes, TRANSMITTING TISSUE SPECIFIC and TOMATO AGAMOUS LIKE11, in the anthers confirmed that the anthers had gained partial pistil identity. Concomitantly, expression of the B-class genes TOMATO APETALA3, TOMATO MADS BOX GENE6 (TM6) and LePISTILLATA was reduced in anthers under continuous mild heat. Plants in which TM6 was partially silenced reacted hypersensitively to temperature elevation with regard to the frequency of pistilloid anthers, pollen viability and pollen quantity. Taken together, these results suggest that high-temperature-induced down-regulation of tomato B-class genes contributes to anther deformations and reduced male fertility. Improving our understanding of how temperature perturbs the molecular mechanisms of anther and pollen development will be important in the view of maintaining agricultural output under current climate changes.

Ascophyllum nodosum Extract Biostimulant Processing and Its Impact on Enhancing Heat Stress Tolerance During Tomato Fruit Set

“…Both extreme temperatures and prolonged periods of moderately elevated temperatures can impact different plant activities leading to reductions in fruit set or fruit yield (Mesihovic et al, 2016). Different tomato plant cultivars growing under chronic mild heat stress showed that pollen release, pollen viability, and anther morphology were major limiting factors for optimum fruit set (Sato et al, 2000;Müller et al, 2016;Xu et al, 2017). One of the main biochemical parameters that influenced pollen viability and development of young tomato fruits during heat stress periods was an optimal carbohydrate metabolism (Pressman et al, 2002;Firon et al, 2006;Li et al, 2012;Zhou et al, 2017).…”

Genome composition and pollen viability of Jatropha (Euphorbiaceae) interspecific hybrids by Genomic In Situ Hybridization (GISH)

“…Such divergent results may be related to the different genotypes used in the crosses of both works or, still, to environmental factors. According to Müller et al (2016), sexual reproduction is very sensitive to environmental perturbations, and pollen viability can vary accordingly under high temperature and in thermotolerant genotypes, as observed for cultivated tomato (Solanum lycopersicum).…”

Transcriptional Basis for Differential Thermosensitivity of Seedlings of Various Tomato Genotypes

“…Studies to define HS-related processes frequently make use of tomato (Solanum lycopersicum L.), which in addition to serving as model for HSR is an important crop [17,21,22]. On the one hand, the thermotolerance mechanisms in tomato have been examined at molecular, physiological and genetic levels and the results have fueled basic models describing the regulation of HSR in plants [23,24].…”