Dehydrin genes and their expression in recalcitrant oak (Quercus robur) embryos

Abstract

In this work, three dehydrin genes, QrDhn1, QrDhn2, QrDhn3, were isolated from recalcitrant oak (Quercus robur). Their expression pattern was analyzed in both zygotic and somatic embryos as well as in vegetative tissues exposed to different kinds of abiotic stresses including desiccation, osmotic stress, and chilling. The QrDhn1 gene encoding for Y(n)SK(n) type dehydrin was expressed during later stages of zygotic embryo development but in somatic embryos only when exposed to osmotic or desiccation stress. In contrast, the other two oak dehydrin genes encoding for putative K(n) type dehydrins were expressed only in somatic embryos (both not-treated and osmotically stressed) and leaves of oak seedlings exposed to desiccation. Behavior of these genes suggests that different dehydrins are involved in processes of seed maturation and response to altered osmotic (water status) conditions in somatic embryos. Revealing further members of dehydrin gene family in recalcitrant oak might contribute to clarify non-orthodox seed behavior as well as identify mechanisms contributing to desiccation tolerance in plants.

Application of biotechnological tools to Quercus improvement

“…The QrDhn1 gene was expressed during later stages of zygotic embryo development but only in somatic embryos when exposed to osmotic or desiccation stress. The other two dehydrin genes were expressed only in somatic embryos (both untreated and osmotically stressed), and the authors suggest that different dehydrins were involved in the process of seed maturation and response to altered osmotic (water status) conditions in somatic embryos (Sunderlikova et al 2009b). These and other members of the dehydrin gene family may contribute to clarifying non-orthodox (oak) seed behavior and to identifying mechanisms related to desiccation tolerance.…”

Dehydrin expression in seeds: an issue of maturation drying

“…In this manner, Šunderlíková et al (2009) reported that apart from the YnSKn type, which is expressed in response to osmotic or desiccation stress in oak embryos, two Kn type dehydrins are expressed constitutively. Moreover, dehydrins are thought to be involved in developmental processes, such as germination (Gumilevskaya and Azarkovich, 2010), and their expression is related to organ type and developmental stage (e.g., Vaseva et al, 2014).…”

“…On a first glance, the situation becomes much more confusing and seems to be contradictory, when considering various recalcitrant plants, whose seeds are reported to express dehydrins, e.g., Castanea sativa (Finch-Savage et al, 1994), Aesculus hippocastaneum, Camellia sinensis (Farrant et al, 1996), Castanospermum australe (Han et al, 1997), Euterpe edulis (Panza et al, 2007), and Quercus robur (Šunderlíková et al, 2009). However, a detailed analysis of the particular situation reveals that also in these cases the order of events also matches the scheme shown in Figure 1: the seeds of theses atypical recalcitrant plants, e.g., those from Quercus robur; Euterpe edulis , indeed undergo a faint maturation drying (e.g., Finch-Savage et al, 1992).…”

LEA polypeptide profiling of recalcitrant and orthodox legume seeds reveals ABI3-regulated LEA protein abundance linked to desiccation tolerance

“…Work has been constrained to detect members of the dehydrin family and showed that they are present in a range of species from different habitats, while apparently being absent from others. Several studies reported the presence of dehydrins in recalcitrant species of temperate origin, whereas these proteins could not be detected in some highly desiccation-sensitive seeds from certain tropical species (Finch-Savage et al , 1994; Farrant et al , 1996; Han et al , 1997; Hinniger et al , 2006; Panza et al , 2007; Sunderlikova et al , 2009; Ismail et al , 2010; Lee et al , 2012). In stored recalcitrant seeds of Quercus robur L., dehydrin mRNA can also be induced by abscisic acid (ABA) and limited drying treatments (Finch-Savage et al , 1994).…”