The Hsp70 Gene family in Solanum Lycopersicum; Genome-wide Identification and Expression Analysis Under Heavy Metals Stresses

Abstract

The Heat shock protein-70 (Hsp70) gene family is one of the protective mechanisms; however, it has not been widely studied in tomatoes. Therefore, the current study provides the first report genome-wide analysis of the Hsp70 gene family in tomato (Solanum lycopersicum L.) under five heavy metals (Cd2+, Co2+, Mn2+, Zn2+, and Fe2+) stresses. We identified 23 candidate genes of the Hsp70 gene family based on the PF00012 domain through bioinformatics studies, including gene structure, distribution, synteny, phylogenetic tree, protein-protein interactions, gene ontology, and previous RNA-seq data analysis followed by qRT-PCR analysis. Based on the phylogenetic analysis, the 23 candidate genes were classified into five subfamilies where the same subfamily contains similar SlHsp70 proteins. Many pairs of SlHsp70 gene duplications have appeared, consisting of tandem and segment duplication. In addition, analysis of previous RNA-seq besides the gene ontology gave us significant evidence about the vital roles of these genes during tomato development and growth. The SlHsp7s showed different responses, which were varied depend on different plant tissues and types of heavy metal. Some of the SlHsp70s were up-regulated after heavy metal exposure, such as Cd2+/SlHsp70-23 and Mn2+/ SlHsp70-8. Still, down-regulated others such as Fe2+/ SlHsp70-18. Finally, our gene expression analysis revealed the significant roles of the Hsp70s, especially, SlHsp70- 3, SlHsp70-8, SlHsp70-12, SlHsp70-19, and SlHsp70-23, with the different heavy metals treatments.

Seed Protection of Solanum lycopersicum with Pythium oligandrum against Alternaria brassicicola and Verticillium albo-atrum

“…For example, transient Hsp70 overexpression in Nicotiana benthamiana inhibits Phytophthora growth [41]. In tomato plants, 23 genes encode Hsp70 proteins, namely, 3 Hsp70 proteins with 92-98 kDa, 2 with 77-80 kDa, 14 with 70-75 kDa, 3 with 62-67 kDa, and 1 with 21 kDa [22]. In our analysis, the increase in Hsp70s (50-70 kDa, Figure 8A) in seed-coated plants may partly account for the priming effect of the interaction between the plant and P. oligandrum.…”

“…In Nicotiana tabacum , this family has 61 members with molecular weights ranging from 16 to 100 kDa, individual members of which are expressed in response to phytohormones, high or low temperature, drought, wounding, or fungal pathogens [ 21 ]. Preliminary results of tomato plants also indicate that 23 candidate genes of the tomato Hsp70 family with molecular weights ranging from 21.3 to 98.8 kDa [ 22 ] and at least seven members of the Hsp90 tomato gene family may be involved in the response to stress, including resistance to Tomato yellow leaf curl virus [ 23 ]. Notwithstanding these advances in the identification of signaling pathways and elicitors by P. oligandrum in activating tomato plant resistance, the extent of protection depends on many other parameters including the application method, i.e., spraying, watering, or seed treatment [ 5 ].…”

Identification of flavonol synthase gene from M. pinnata and its functional elucidation using cowpea genome

“…The chromosome localization of FLSgenes was depicted by Phenogram Plot (http://visualization.ritchielab.psu.edu/phenograms/plot). The genes were assembled according to the following criteria: the identity of the align sequences was greater than 80% and the aligned nucleotide coding sequence spanned 80% of the longer gene [31]. Tandemly duplicated genes have a physical spacing of 50kb between two homologous genes [32].…”