A Sugarcane G-Protein-Coupled Receptor, ShGPCR1, Confers Tolerance to Multiple Abiotic Stresses

Abstract

Sugarcane (Saccharum spp.) is a prominent source of sugar and serves as bioenergy/biomass feedstock globally. Multiple biotic and abiotic stresses, including drought, salinity, and cold, adversely affect sugarcane yield. G-protein-coupled receptors (GPCRs) are components of G-protein-mediated signaling affecting plant growth, development, and stress responses. Here, we identified a GPCR-like protein (ShGPCR1) from sugarcane and energy cane (Saccharum spp. hybrids) and characterized its function in conferring tolerance to multiple abiotic stresses. ShGPCR1 protein sequence contained nine predicted transmembrane (TM) domains connected by four extracellular and four intracellular loops, which could interact with various ligands and heterotrimeric G proteins in the cells. ShGPCR1 sequence displayed other signature features of a GPCR, such as a putative guanidine triphosphate (GTP)-binding domain, as well as multiple myristoylation and protein phosphorylation sites, presumably important for its biochemical function. Expression of ShGPCR1 was upregulated by drought, salinity, and cold stresses. Subcellular imaging and calcium (Ca2+) measurements revealed that ShGPCR1 predominantly localized to the plasma membrane and enhanced intracellular Ca2+ levels in response to GTP, respectively. Furthermore, constitutive overexpression of ShGPCR1 in sugarcane conferred tolerance to the three stressors. The stress-tolerance phenotype of the transgenic lines corresponded with activation of multiple drought-, salinity-, and cold-stress marker genes, such as Saccharum spp. LATE EMBRYOGENESIS ABUNDANT, DEHYDRIN, DROUGHT RESPONSIVE 4, GALACTINOL SYNTHASE, ETHYLENE RESPONSIVE FACTOR 3, SALT OVERLY SENSITIVE 1, VACUOLAR Na+/H+ ANTIPORTER 1, NAM/ATAF1/2/CUC2, COLD RESPONSIVE FACTOR 2, and ALCOHOL DEHYDROGENASE 3. We suggest that ShGPCR1 plays a key role in conferring tolerance to multiple abiotic stresses, and the engineered lines may be useful to enhance sugarcane production in marginal environments with fewer resources.

Functional Analysis of Pheromone Biosynthesis Activating Neuropeptide Receptor Isoforms in Maruca vitrata

“…In addition, four N-myristoylation sites were identified in the MviPBANR isoforms (Figure 1). N-myristoylation sites in GPCRs are important in the translational process and are related to protein anchoring on the membrane and cell signal transduction regulation [35,36].…”

“…However, RNAi suppression was performed on the C-terminal tail of MviPBANR-C, which is different from that of MviPBANR-B. Except for an Nmyristoylation site, the C-terminal tail region used for RNAi suppression of MviPBANR-C does not contain an important motif for ligand binding, suggesting that N-myristoylation suppression may negatively affect cell signal transduction (Figure 5) [35,36].…”

In Silico Dissection of Regulatory Regions of PHT Genes from Saccharum spp. Hybrid and Sorghum bicolor and Expression Analysis of PHT Promoters under Osmotic Stress Conditions in Tobacco

“…is an important commercial crop, grown worldwide for biofuel production, and accounting for 80% of global sugar [1]. Environmental factors cause significant economic damage to sugarcane and affect growth and production by 30 to 60% [2]. Abiotic stress is acknowledged as an important environmental risk factors to agricultural plant productivity and quality.…”