what is the function of hydothodes
Answers
Answer:
Hydathodes are the structures that discharge water from the interior of the leaf to its surface in a process called guttation. We have examined the detailed structure and possible function of the hydathode in Arabidopsis thaliana. We found that the guttation actually occurred on the leaf margin of Arabidopsis plants under the conditions of high humidity and in the dark. It is thought that guttation is a necessary process to absorb solutes when transpiration is suppressed. The structure of hydathode of Arabidopsis had a typical characteristic of the epithem hydathode, and it consists of epidermis, water pores, epithem and tracheary elements. Previously we found that the alphaVPE and gammaVPE (Vacuolar Processing Enzyme) genes predominantly expressed in the hydathodes. Arabidopsis plants have three homologues of VPEs; the betaVPE gene predominantly expressed in the seed and the alphaVPE and gammaVPE genes expressed in vegetative tisseus. VPEs are asparagine specific proteinases and responsible for the maturation of seed-storage proteins. We have thought that the alphaVPE and gammaVPE proteins process various vacuolar proteins in the vegetative tissues. Therefore, the expressions of VPE homologues in the hydathodes reflect the possibility that the vacuoles have active function and play an important role. We found that the gene expression of alphaVPE was regulated by the concentration of apoplastic solutes in the hydathode. We also found numerous multivesicular bodies in the epithem cells from electron micrographs. To clarify the relationships between the expression of VPE genes and the multivesicular bodies, we showed that the fluorescent dye lucifer yellow was predominantly incorporated into the vacuoles of epithem cells via multivesicular bodies. These findings suggest that the epithem in the hydathode act as a site for recovery of apoplastic solutes, and the vacuoles have an active function of storage compartments.
Answer:
A hydathode is a type of pore, commonly found in angiosperms, that secretes water through pores in the epidermis or leaf margin, typically at the tip of a marginal tooth or serration.