Overexpression of calmodulin-like (ShCML44) stress-responsive gene from Solanum habrochaites enhances tolerance to multiple abiotic stresses

Abstract

Calmodulin-like (CML) proteins are important Ca2+ sensors, which play significant role in mediating plant stress tolerance. In the present study, cold responsive calmodulin-like (ShCML44) gene was isolated from cold tolerant wild tomato (Solanum habrochaites), and functionally characterized. The ShCML44 was differentially expressed in all plant tissues including root, stem, leaf, flower and fruit, and was strongly up-regulated under cold, drought and salinity stresses along with plant growth hormones. Under cold stress, progressive increase in the expression of ShCML44 was observed particularly in cold-tolerant S. habrochaites. The ShCML44-overexpressed plants showed greater tolerance to cold, drought, and salinity stresses, and recorded higher germination and better seedling growth. Transgenic tomato plants demonstrated higher antioxidant enzymes activity, gas exchange and water retention capacity with lower malondialdehyde accumulation and membrane damage under cold and drought stresses compared to wild-type. Moreover, transgenic plants exhibited reduced reactive oxygen species and higher relative water contents under cold and drought stress, respectively. Greater stress tolerance of transgenic plants was further reflected by the up-/down-regulation of stress-related genes including SOD, GST, CAT, POD, LOX, PR and ERD. In crux, these results strengthen the molecular understanding of ShCML44 gene to improve the abiotic stress tolerance in tomato.

The Effect of Abiotic Stress Conditions on Expression of Calmodulin (CaM) and Calmodulin-Like (CML) Genes in Wild-Growing Grapevine Vitis amurensis

“…Recently, a number of studies demonstrated that overexpression of plant CaM and CML genes can improve plant resistance to abiotic stresses [17][18][19][20]. For example, overexpression of the ShCML44 gene isolated from cold tolerant wild tomato enhanced the tolerance of a stress-sensitive tomato to cold, drought, and salinity [18]. According to our data, a homologous VaCML44 gene shared 66% protein similarity to ShCML44 and was up-regulated under cold and salinity stress treatments (Figure 2).…”

“…Recently, a number of studies demonstrated that overexpression of plant CaM and CML genes can improve plant resistance to abiotic stresses [17][18][19][20]. For example, overexpression of the ShCML44 gene isolated from cold tolerant wild tomato enhanced the tolerance of a stress-sensitive tomato to cold, drought, and salinity [18].…”

Overexpression of OsERF48 causes regulation of OsCML16, a calmodulin‐like protein gene that enhances root growth and drought tolerance

“…These genes were associated with stress signalling, carbohydrate metabolism, cell‐wall proteins and drought response and included OsCML16 , encoding a calmodulin‐like protein, which was located at the centre of our OsERF48 co‐regulatory network, indicating an important regulatory role (Figure a). Many studies have suggested that CMLs are major calcium ion sensors and function in mediating plant stress tolerance (Magnan et al ., ; Munir et al ., ; Park et al ., ; Xu et al ., ). Other lines of evidence also indicate that downstream target genes regulated by CMLs include kinases, metabolic proteins, cytoskeletal proteins, ion channels and pumps, and TFs (Zeng et al ., ).…”

“…These interactions mediate the regulation of various target proteins, such as protein kinases/phosphatases, transcription factors, metabolic enzymes, ion channels and structural proteins (reviewed by Reddy et al ., ; Zeng et al ., ). There is considerable evidence that CMLs play a critical role in Ca 2+ signalling during plant adaptations to abiotic stress in tomato ( Solanum lycopersicum ) (Munir et al ., ), A. thaliana (Magnan et al ., ; Park et al ., ) and rice (Xu et al ., ). However, the molecular mechanisms by which CMLs regulate stress responses remain unknown.…”

Drought and heat stress-related proteins: an update about their functional relevance in imparting stress tolerance in agricultural crops

“…Their roles in stress tolerance were validated involving transgenic studies. For example, a putative calmodulin-like (ShCML44) gene isolated from a cold-resilient variety of wild tomato (Solanum habrochaites) conferred enhanced resilience to drought conditions in transmutant lines (Munir et al 2016). Similarly, a novel CML multi-stress-responsive gene 2, OsMSR2, from rice imparts drought stress resilience in plants via ABA-mediated signaling in transgenic Arabidopsis (Xu et al 2011).…”