Free amino acids in unhardened and cold‐hardened winter wheat crowns

Abstract

The free amino acids proline and glutamic acid increased in the crown of winter wheat in all treatments when exposed to coldhardening. Glutamine also increased except when 90-80 N-P fertilizer was applied. The increase of proline and glutamic acid was enhanced with the application of P but counteracted by N. This enhancement was smaller with glutamine. The decrease of threonine, tyrosine, phenylalanine, lysine and tf-aminobutyric acid with cold-hardening was not counteracted by application of N and P.However, isoleucine in cold-hardened winter wheat increased with the application of 180-0 fertilizer and aspartic acid increased when P was added. The increase in alanine with cold-hardening was enhanced 1104 KALDY AND FREYMAN by P alone but counteracted by N-P treatments. The marked increase in proline during cold-hardening could be useful in the detection of cold-hardiness in winter wheats.

Classification of Genotypes of Eucalyptus Globulus Under Cold Conditions Using Their Free Amino Acids Content on Leaves and Regularized Discriminant Analysis (Rda)

“…These results are in agreement with some previously reported works, where Asp, Glu, Gln, Arg and Ala levels incremented under low non-freezing temperatures 30,31 , and a diminution of some of them such as Glu, when freezing temperatures were applied over the plants was observed 23 ; however, not all these amino acids could be responsible for the increased cold resistance of the genotypes. Table 2.…”

“…Several others works [24][25][26] found relationships between accumulation of Pro and freezing tolerance, although other results suggest that Pro increments are due to the exposure to cold temperatures rather than an enhanced freezing tolerance 22,27,28 . Few studies have analyzed other amino acids [29][30][31] . Variations in the content of Glu, Gln, Ala, Asp and Asn after cold conditions have been reported in wheat 30,31 .…”

“…Few studies have analyzed other amino acids [29][30][31] . Variations in the content of Glu, Gln, Ala, Asp and Asn after cold conditions have been reported in wheat 30,31 . 29 found higher levels of Pro, Gln and Glu and greater differences of amino acid content for three ecotypes of Poa annua L. after an acclimatization at subzero temperatures (-2ºC); however the amino acid levels were not related to the differential freezing tolerance of the ecotypes.…”

Effect of silicon on chilling-induced changes of solutes, antioxidants, and membrane stability in seashore paspalum turfgrass

“…Dörffling et al (1998) reported the existence of a close relationship between coldinduced proline accumulation and cold adaptation in wheat (Triticum aestivum L.). Kaldy and Freyman (1984), Naidu et al (1991) and Dionne et al (2001) also observed an increase of proline in leaves and crowns of wheat and annual bluegrass (Poa annua L.) which was exposed to low temperature. In addition, the constitutively freeze-tolerant single-gene arabidopsis mutant (eskimo1) was higher in both proline and sugar (Xin and Browse 1998).…”

Abscisic Acid and Proline Levels in Cold Hardened Winter Wheat Leaves in Relation to Variety‐Specific Differences in Freezing Resistance

“…Similar to dry weight, proline levels increased during cold hardening parallel to the increase in freezing resistance. KALDY and FREYMAN (1984) to our knowledge were the first who proposed to use the increase in proiine during cold hardening for the detection of cold hardiness in winter wheat breeding programs. This confirms and extends earlier studies with winter wheat (PERUANSKI and STASENKO 1980, KALDY and FREVMAN 1984, LALK and DORFFLING 1985, MACHACKOVA et al 1988), which were performed, however, with a very limited number of varieties.…”