Fig 1.
Morphological characteristics (A), fresh matter (B) and dry matter (C) of micropropagated plantlets of the sugarcane cultivars CB38-22 and RB855536 in liquid MS culture media with 0 mM NaCl (control) or 180 mM NaCl. Bars = 0.75 cm. The same letter above the bars indicates no significant difference according to Tukey’s test at 5% probability.
Fig 2.
Functional analysis of proteins showing differential abundance between cultivars CB38-22 and RB855536 under salt stress (180 mM NaCl) compared with their respective controls (without NaCl).
A = CB-180/CB-0. B = RB-180/RB-0. The log2 values of the fold changes obtained for each cultivar under salt stress compared with their respective controls were used to determine the levels of protein abundance. The up-regulated proteins showed log2 values greater than 0.5, and the down-regulated proteins showed log2 values less than -0.5.
Fig 3.
Protein mapping of the CB38-22 and RB855536 cultivars under salt stress (180 mM NaCl) compared with their respective controls (without NaCl).
A = CB-180/CB-0. B = RB-180/RB-0. All proteins with functions related to “response to biotic and abiotic stresses” are displayed on the maps. The log2 values of the fold changes obtained for each cultivar under salt stress compared to their respective controls were used to determine the levels of protein abundance.
Fig 4.
Differential abundance of proteins with important roles in the response of sugarcane plants to salt stress.
The abundances of glyceraldehyde-3-phosphate dehydrogenase (A), calcium-dependent protein kinase 1 (B), photosystem I subunit I (C), phospholipase D alpha 1 (D), and translation initiation factor 2 (E) are shown for both cultivars under control and salt stress conditions. The bars represent the means ± SD (n = 3). CB-0 and RB-0 = cultivar CB38-22 and RB855536, respectively, cultured without NaCl (controls); CB-180 and RB-180 = cultivars CB38-22 and RB855536, respectively, cultured with 180 mM NaCl.
Table 1.
Proteins that were up-regulated or down-regulated under salt stress compared with their respective controls (CB-180/CB-0; RB-180/RB-0*) and proteins showing differential regulation between the two cultivars (RB-180/CB-180).
Fig 5.
Proposed scheme of the major regulated proteins affecting ionic and osmotic homeostasis and thereby yielding a greater tolerance to salt stress in sugarcane.
The blue arrows represent the more abundant proteins and red arrows represent the less abundant proteins when both cultivars were compared under salt stress.