Salt Stress-Induced Alterations in the Root Proteome ofAmaranthus cruentusL.

Abstract

Salt stress is one of the major factors limiting crop productivity worldwide. Amaranth is a highly nutritious pseudocereal with remarkable nutraceutical properties; it is also a stress-tolerant plant, making it an alternative crop for sustainable food production in semiarid conditions. A two-dimensional electrophoresis gel coupled with a liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) approach was applied in order to analyze the changes in amaranth root protein accumulation in plants subjected to salt stress under hydroponic conditions during the osmotic phase (1 h), after recovery (24 h), and during the ionic phase of salt stress (168 h). A total of 101 protein spots were differentially accumulated in response to stress, in which 77 were successfully identified by LC-MS/MS and a database search against public and amaranth transcriptome databases. The resulting proteins were grouped into different categories of biological processes according to Gene Ontology. The identification of several protein isoforms with a change in pI and/or molecular weight reveals the importance of the salt-stress-induced posttranslational modifications in stress tolerance. Interestingly stress-responsive proteins unique to amaranth, for example, Ah24, were identified. Amaranth is a stress-tolerant alternative crop for sustainable food production, and the understanding of amaranth's stress tolerance mechanisms will provide valuable input to improve stress tolerance of other crop plants.

Insights on Structure and Function of a Late Embryogenesis Abundant Protein from Amaranthus cruentus: An Intrinsically Disordered Protein Involved in Protection against Desiccation, Oxidant Conditions, and Osmotic Stress

“…Tissues were collected from three biological replicates containing three plants for each replicate. Samples were collected and immediately frozen in liquid nitrogen and milled to a fine powder as reported before (Huerta-Ocampo et al, 2014). The powder was suspended in extraction buffer (1:10 w/v) containing 7 M urea, 2 M thiourea, 2% Triton X-100, and 0.1 M 2-mercaptoethanol.…”

“…Current interest in amaranth plants is also related to their extraordinary adaptability to grow in adverse weather conditions (Brenner et al, 2000). Amaranth is resistant against several types of stresses such as pest (Valdes-Rodríguez et al, 2007), heat (Maughan et al, 2009), drought (Huerta-Ocampo et al, 2011), and salinity (Aguilar-Hernández et al, 2011; Huerta-Ocampo et al, 2014). The recent report of Amaranthus cruentus seed proteome by 2D-PAGE revealed the over-accumulation of one spot identified as a LEA protein (Maldonado-Cervantes et al, 2014).…”

A virus‐induced gene‐silencing system for functional genetics in a betalainic species, Amaranthus tricolor (Amaranthaceae)

“…Amaranth has advantages of being a protein‐rich C 4 pseudo‐cereal that can be adapted to cultivation in a wide range of environments, with good tolerance of drought and salinity (Kong et al., ; Teng et al., ). It also has superior water use efficiency compared to many other C 3 and C 4 crops (Omamt et al., ; Huerta‐Ocampo et al., ). Amaranths naturally produce betalains, which may contribute to their agronomic and nutritional advantages.…”

Secondary Metabolism in Amaranthus spp. — A Genomic Approach to Understand Its Diversity and Responsiveness to Stress in Marginally Studied Crops with High Agronomic Potential

“…Also, enhanced drought tolerance has been generated in several different transgenic plants transformed with genes encoding diverse types of antioxidant-related enzymes or metabolites (e.g., SOD, APX, monodehydroascorbate reductase, and tocopherol cyclase, a key enzyme of tocopherol biosynthesis, [22]). Regarding grain amaranth, a series of proteomic studies performed in plants exposed to drought and saline stress detected the accumulation of various antioxidant enzymes, similar to those mentioned above [23,24]. In addition, the participation of antioxidant genes, such as AhCAT, AhAPX, and AhSOD, was implied by findings showing their induced-up-regulation in grain amaranth plants primed to resist infection by pathogenic bacteria [15].…”