Hyperhydricity in Plant Tissue Culture

Abstract

Hyperhydricity is the most common physiological disorder in in vitro plant cultivation. It is characterized by certain anatomical, morphological, physiological, and metabolic disturbances. Hyperhydricity significantly complicates the use of cell and tissue culture in research, reduces the efficiency of clonal micropropagation and the quality of seedlings, prevents the adaptation of plants in vivo, and can lead to significant losses of plant material. This review considers the main symptoms and causes of hyperhydricity, such as oxidative stress, impaired nitrogen metabolism, and the imbalance of endogenous hormones. The main factors influencing the level of hyperhydricity of plants in vitro are the mineral and hormonal composition of a medium and cultivation conditions, in particular the aeration of cultivation vessels. Based on these factors, various approaches are proposed to eliminate hyperhydricity, such as varying the mineral and hormonal composition of the medium, the use of exogenous additives, aeration systems, and specific lighting. However, not all methods used are universal in eliminating the symptoms of hyperhydricity. Therefore, the study of hyperhydricity requires a comprehensive approach, and measures aimed at its elimination should be complex and species-specific.

Effects of Monochromatic Light on Growth and Quality of Pistacia vera L.

“…HH is considered one of the most common and unfavorable physiological disorders observed during micropropagation. It is generally distinguished by specific anatomical, morphological, physiological, and metabolic changes resembling stress effects [ 41 ]. One of the main causes may be high relative humidity and gas accumulation (mostly CO 2 and ethylene) in the environment of sealed culture vessels [ 42 ], but it may also be due to high cytokinin concentration or high water availability in the medium.…”

Characterization of gelling agents in callus inducing media: Physical properties and their effect on callus development

“…On the other hand, enhanced water availability in the Gelrite media could facilitate cellular adhesion, potentially leading to the observed compact morphology of the calli. An excess of water can lead to vitrification, a process that potentially disrupts all applications, and therefore should be carefully considered 52 . A future histology analysis can contribute to a deeper understanding of the cellular and tissue-level changes.…”

Optimizing Medium Composition and Environmental Culture Condition Enhances Antioxidant Enzymes, Recovers Gypsophila paniculata L. Hyperhydric Shoots and Improves Rooting In Vitro

“…The commercial micropropagation industry of G. paniculata is hindered by hyperhydricity [ 6 ]. The main factors influencing the hyperhydricity of in vitro propagated plants are the minerals, the hormonal composition of the medium and culture conditions [ 52 ]. The optimization of the medium chemical components and the regulation of the environmental culture conditions could be useful to overcome hyperhydricity in tissue cultured plants.…”

“…For improving the micropropagation protocol of a plant species, the concentration of the two nitrogen salts in MS medium (NH 4 NO 3 and KNO 3 ) should be modified and optimized according to the plant species. It would be favorable and more practical than that of separated ions [ 52 ]. Increasing N improved shoot elongation and quality, but reduced the number of shoots in most red raspberry cultivars ( Rubus idaeus L.) [ 53 ].…”