Improved frost tolerance and winter hardiness in proline overaccumulating winter wheat mutants obtained by in vitro-selection is associated with increased carbohydrate, soluble protein and abscisic acid (ABA) levels

Abstract

In previous studies in vitro-selection of proline overaccumulating lines of winter wheat (Triticum sativum L. cv. Jo 3063) with increased frost tolerance was reported. These traits were found to be genetically stable. In the present study the improvement of frost tolerance (winter hardiness) under field conditions is confirmed for F 7 progenies of the mutants. Moreover, the mutants accumulated higher levels of glucose and fructose, soluble protein and abscisic acid (ABA) in addition to proline than the wild type under cold hardening conditions in a growth chamber as well as under cold hardening field conditions. ABA and proline levels peaked when the temperature decreased, whereas carbohydrate levels increased more slowly at decreasing temperature. Soluble protein levels also increased during cold hardening, but in addition showed sharp declines during frost periods. Increased carbohydrate levels of the mutants were associated with lower osmotic potential values. The differences in carbohydrate, protein and ABA levels between the mutants and the wild type are probably due to pleiotropic effects of the mutation.

Dehydrin and proline content in Brassica napus and B. carinata under cold stress at two irradiances

“…Although proline was not significantly accumulated as a result of cold treatment in our experiments, the literature contains a number of reports that cold treatment does induce the accumulation of proline (Atici et al 2003) and that there is a positive correlation between the level of proline in the leaf and FT (McClinchey and Kott 2008, Dörffling et al 2009, Walker et al 2010). However, in cauliflower, Fuller et al (2006 suggested the opposite trend, specifically that FT was associated with lower proline contents.…”

“…In cell cultures of alfalfa (Parmentier-Line et al 2002) and blueberry (Wolfraim et al 1993), dehydrin content was enhanced by the imposition of a cold treatment. Proline, which has been associated with the general stress response (Kavi Kishor et al 2005, Kumar et al 2010, Li et al 2010, Toka et al 2010, may also be cryoprotective, since proline overproducers display an enhanced cold tolerance (Patton et al 2007, McClinchey and Kott 2008, Dörffling et al 2009, Pociecha et al 2009, Gothandam et al 2010. The transgenic embryo of hybrid larch (Larix × leptoeuropaea) with increased proline content was resistant to cold, salt, and freezing stresses (Gleeson et al 2005).…”

Alleviation of Osmotic Stress Effects by Exogenous Application of Salicylic or Abscisic Acid on Wheat Seedlings

“…ABA increase under stress is a common reaction in the plant kingdom. A greater accumulation of ABA under stress conditions in the resistant cultivar compared to the susceptible one was also observed under other types of stress, e.g., under frost in wheat [56] and under chilling in maize [57]. The higher ABA level in the tolerant cultivar increases its stress tolerance through stomata closure reducing transpiration and improving water relations (Table 1, Figure 1), and alleviates the negative after effects of stress on the yield (Table 3).…”

In vitro slow growth storage of Senecio macrophyllus shoots

“…ABA is known as a growth retardant on in vitro growth. ABA treatment usually increases cold tolerance in stored plant material by increasing the expression of COR/LEA genes (Kobayashi et al 2008) and accumulation of proline (Dörffling et al 2009). A benefit for shoot survival is also displayed by ABA or/and proline pretreatment of Brassica campestris and B. napus (Wilen et al 1994), and Begonia x erythrophylla (Burritt 2008).…”