Genome-wide identification of MST, SUT and SWEET family sugar transporters in root parasitic angiosperms and analysis of their expression during host parasitism

Abstract

Background Root parasitic weeds are a major constraint to crop production worldwide causing significant yearly losses in yield and economic value. These parasites cause their destruction by attaching to their hosts with a unique organ, the haustorium, that allows them to obtain the nutrients (sugars, amino acids, etc.) needed to complete their lifecycle. Parasitic weeds differ in their nutritional requirements and degree of host dependency and the differential expression of sugar transporters is likely to be a critical component in the parasite’s post-attachment survival. Results We identified gene families encoding monosaccharide transporters (MSTs), sucrose transporters (SUTs), and SWEETs (Sugars Will Eventually be Exported Transporters) in three root-parasitic weeds differing in host dependency: Triphysaria versicolor (facultative hemiparasite), Phelipanche aegyptiaca (holoparasite), and Striga hermonthica (obligate hemiparasite). The phylogenetic relationship and differential expression profiles of these genes throughout parasite development were examined to uncover differences existing among parasites with different levels of host dependence. Differences in estimated gene numbers are found among the three parasites, and orthologs within the different sugar transporter gene families are found to be either conserved among the parasites in their expression profiles throughout development, or to display parasite-specific differences in developmentally-timed expression. For example, MST genes in the pGLT clade express most highly before host connection in Striga and Triphysaria but not Phelipanche , whereas genes in the MST ERD6-like clade are highly expressed in the post-connection growth stages of Phelipanche but highest in the germination and reproduction stages in Striga. Whether such differences reflect changes resulting from differential host dependence levels is not known. Conclusions While it is tempting to speculate that differences in estimated gene numbers and expression profiles among members of MST, SUT and SWEET gene families in Phelipanche , Striga and Triphysaria reflect the parasites’ levels of host dependence, additional evidence that altered transporter gene expression is causative versus consequential is needed. Our findings identify potential targets for directed manipulation that will allow for a better understanding of the nutrient transport process and perhaps a means for controlling the devastating effects of these parasites on crop productivity. Electronic supplementary material The online version of this article (10.1186/s12870-019-1786-y) contains supplementary material, which is available t...

Genome-wide identification, expression, and association analysis of the monosaccharide transporter (MST) gene family in peanut (Arachis hypogaea L.)

“…To identify MST genes in peanut, the predicted protein sequences were downloaded from PeanutBase (https ://peanu tbase .org) (Arachis duranensis V14167: A subgenome; Arachis ipaensis K30076: B subgenome; Bertioli et al 2016). The Sugar_tr domain (PF00083) (Deng et al 2019;Misra et al 2019) was identified using HMMER 3.0 program at a standard E value < 1 × 10 -5 . Conserved domain searches were performed against the conserved domain database in NCBI (https ://www.ncbi.nlm.nih.gov/Struc ture/cdd/wrpsb .cgi?).…”

A Transcriptomic Approach Provides Insights on the Mycorrhizal Symbiosis of the Mediterranean Orchid Limodorum abortivum in Nature

“…These data indicate that SWEET transporters may play important roles in mycoheterotrophic developmental stages as well as in adult plants of orchid species that rely on the mycorrhizal fungal symbiont for carbon (i.e., mycoheterotrophic and mixotrophic orchids). The role and localization of these different sugar transporters require further investigations, but it is interesting that several MST and SWEET transporters were also regulated during the parasitic interaction of plant species that directly obtain carbon from their host plants [ 66 ].…”

Tonoplast Inositol Transporters: Roles in Plant Abiotic Stress Response and Crosstalk with Other Signals

“…Among those studied sugar transporter MONOSACCHARIDE TRANSPORTERS (MSTs) SUGARS WILL EVENTUALLY BE EXPORTED TRANSPORTER (SWEETs and SUCROSE TRANSPORTERS (SUTs). MSTs represents a large family of seven subgroups including EARLY RESPONSE TO DEHYDRATION (ERD6), SUGAR TRANSPORT PROTEINS (STP), PLASTID GLUCOSE TRANSPORTER (pGlcT), INOSITOL TRANSPORTERS (INT), VACUOLAR GLUCOSE TRANSPORTER (VGT), TONOPLAST SUGAR TRANSPORTERS (TST), and POLYOL/MONOSACCHARIDE TRANSPORTERS (PLT) [42][43][44]. Sucrose transporters' activities are strictly linked to the stimuli levels; their sensibilities enable plant adaptation to different external changes as small as it is such as temperature, drought, pathogen attack, saline, and other stresses.…”