Changes in apoplastic peroxidase activity and cell wall composition are associated with cold‐induced morpho‐anatomical plasticity of wheat leaves

Abstract

Temperate grasses, such as wheat, become compact plants with small thick leaves after exposure to low temperature. These responses are associated with cold hardiness, but their underlying mechanisms remain largely unknown. Here we analyse the effects of low temperature on leaf morpho-anatomical structure, cell wall composition and activity of extracellular peroxidases, which play key roles in cell elongation and cell wall thickening, in two wheat cultivars with contrasting cold-hardening ability. A combined microscopy and biochemical approach was applied to study actively growing leaves of winter (ProINTA-Pincén) and spring (Buck-Patacón) wheat developed under constant warm (25 °C) or cool (5 °C) temperature. Cold-grown plants had shorter leaves but longer inter-stomatal epidermal cells than warm-grown plants. They had thicker walls in metaxylem vessels and mestome sheath cells, paralleled with accumulation of wall components, predominantly hemicellulose. These effects were more pronounced in the winter cultivar (Pincén). Cold also induced a sharp decrease in apoplastic peroxidase activity within the leaf elongating zone of Pincén, and a three-fold increase in the distal mature zone of the leaf. This was consistent with the enhanced cell length and thicker cell walls in this cultivar at 5 °C. The different response to low temperature of apoplastic peroxidase activity and hemicellulose between leaf zones and cultivar types suggests they might play a central role in the development of cold-induced compact morphology and cold hardening. New insights are presented on the potential temperature-driven role of peroxidases and hemicellulose in cell wall dynamics of grasses.

The Size-Dependent Effects of Silver Nanoparticles on Germination, Early Seedling Development and Polar Metabolite Profile of Wheat (Triticum aestivum L.)

“…( Table 1 ). This monosaccharide is derived from the hydrolysis of raffinose, present in dry wheat grains [ 69 ], and is a substrate for the synthesis of arabinogalactans in cell walls [ 70 ] as well as arabinogalactan proteins in wheat seedlings roots [ 71 ]. Additionally, the concentration of 1-kestose was higher than in control (5.5–6.0 and 4.6 mg/g DW, respectively), while myo-inositol and maltose remained unaffected, regardless of the NPs size ( Table S1 ).…”

ISSR molecular markers and anatomical structures can assist in rapid and directional screening of cold-tolerant seedling mutants of medicinal and ornamental plant in Plumbago indica L.

“…Our study also found that the cold-tolerant mutant strains SA15, SA19, SA23, and SA24 had reduced relative MDA content, and increased SOD, CAT and POD activities, and were therefore more cold-tolerant, which also indicated that plants would mobilize different levels of antioxidant enzyme activity in the face of abiotic stress to respond to or alleviate injury ( Li et al., 2022b ; Duan et al., 2023 ). In addition, peroxidase plays a key role in cell elongation and cell wall thickening ( Lorenzo et al., 2019 ), and the thickening of leaves and the thickening of epidermal cells found in this study all show the functional significance of mutants with stronger production of peroxidase to eliminate peroxide damage.…”

“…Plant size reduction due to low temperature is a common phenomenon in temperate species and the phenomenon is considered to be an adaptive value of the plant to the cold environment ( Lorenzo et al., 2019 ). At the same time, mutagenesis can cause dwarf due to damage to cells ( Li et al., 2022c ).…”

“…The cold-resistant mutant strain screened in this case was also found to have dwarfed plants, which will be an important shape for future field performance to follow. Based on plant variation, cold environmental conditions lead to longer leaf epidermal cell margins, increased leaf thickness, and smaller leaves ( Lorenzo et al., 2019 ). In turn, the increase in leaf thickness was correlated with the increase in the size of the mesophyll cell ( Wang et al., 2008 ) or the number of mesophyll cell layers ( Dumlao et al., 2012 ).…”

Molecular mechanisms of plant acclimation to changing environments

“…Exposure to cold is accompanied by morphological changes in leaf anatomy that render plants more resistant to freezing temperatures. Comparing the effects of temperature on leaf anatomy of spring and winter varieties of wheat with contrasting cold-hardening ability, Lorenzo et al (2019) identified apoplastic peroxidases and hemicellulose activity in leaf zones as key regulators of changes in cell wall structure that lead to cold hardiness in grasses.…”