Fourier transform mid-infrared (FT-MIR) spectroscopy has been extensively used as a potent, fast and non-destructive procedure for analyzing cell wall architectures, with the capacity to provide abundant information about their polymers, functional groups, and in muro entanglement. In conjunction with multivariate analyses, this method has proved to be a valuable tool for tracking alterations in cell walls. The present review examines recent progress in the use of FT-MIR spectroscopy to monitor cell wall changes occurring in muro as a result of various factors, such as growth and development processes, genetic modifications, exposition or habituation to cellulose biosynthesis inhibitors and responses to other abiotic or biotic stresses, as well as its biotechnological applications.

Orchid micropropagation of species Euchile mariae was achieved from the in vitro culture of protocorms sections, obtained from the germination of seeds. The top and bottom protocorms sections, used as explants, were cultivated in modified MS culture medium, added with different concentrations of α-naph- thaleneacetic acid (NAA) and 6-benzylaminopurine (BA). The morphogenetic response obtained of both types of explants, was the formation of protocorm like bodies (PLB’s), that gave place to the formation of new plantlets. Of two tested explants the biggest formation of PLB’s was obtained from the bottom proto- corms sections. The acclimatization of the plantlets was successful, with a 100% percent survival. Plant cell tissue culture represents a useful alternative for the study, conservation and massive propagation of this and other endangered species.

From the germination of seeds of Euchile mariae in modified MS medium, the formation of pro- tocorms was achieved. Once these reached an average size from 2 to 5 mm long and the formation of his first leaf primordium, they were used like explants to induce a morphogenetic response. Through in vitro culture of top and bottom protocorms sections, were obtained differentiated structures from asexual origin. Their morphology was similar to protocorms obtained from the germination of seeds, in this way we call them protocorm like bodies (PLB’s). Through of the histological analysis of these structures it was possible to reveal that these PLB’s turned out to be somatic embryos. The histochemical tests demonstrate the pres- ence of cellular contents like: proteins, lipids and starch; both in the cells of the embryos as well as in the cells of initial tissues.

Ancymidol inhibits the incorporation of cellulose into cell walls of maize cell cultures in a gibberellin-independent manner, impairing cell growth; the reduction in the cellulose content is compensated with xylans. Ancymidol is a plant growth retardant which impairs gibberellin biosynthesis. It has been reported to inhibit cellulose synthesis by tobacco cells, based on its cell-malforming effects. To ascertain the putative role of ancymidol as a cellulose biosynthesis inhibitor, we conducted a biochemical study of its effect on cell growth and cell wall metabolism in maize cultured cells. Ancymidol concentrations ≤ 500 µM progressively reduced cell growth and induced globular cell shape without affecting cell viability. However, cell growth and viability were strongly reduced by ancymidol concentrations ≥ 1.5 mM. The I value for the effect of ancymidol on FW gain was 658 µM. A reversal of the inhibitory effects on cell growth was observed when 500 µM ancymidol-treated cultures were supplemented with 100 µM GA. Ancymidol impaired the accumulation of cellulose in cell walls, as monitored by FTIR spectroscopy. Cells treated with 500 µM ancymidol showed a ~ 60% reduction in cellulose content, with no further change as the ancymidol concentration increased. Cellulose content was partially restored by 100 µM GA. Radiolabeling experiments confirmed that ancymidol reduced the incorporation of [C]glucose into α-cellulose and this reduction was not reverted by the simultaneous application of GA. RT-PCR analysis indicated that the cellulose biosynthesis inhibition caused by ancymidol is not related to a downregulation of ZmCesA gene expression. Additionally, ancymidol treatment increased the incorporation of [H]arabinose into a hemicellulose-enriched fraction, and up-regulated ZmIRX9 and ZmIRX10L gene expression, indicating an enhancement in the biosynthesis of arabinoxylans as a compensatory response to cellulose reduction.