Endogenous hormonal content during grain development in hexaploid and tetraploid wheat

Abstract

A pot experiment was conducted in the rabi (post rainy) seasons of 2001 and 2002 to study the genotypic differences in grain growth rate and endogenous hormonal content in the developing grains of hexaploid and tetraploid wheat. The endogenous hormonal contents of grains in both the ploidy levels had changed in sequence. At 5 days after anthesis (DAA), gibberellic acid (GA 3 ); at 15 DAA (rapid growth phase), indole-acetic acid (IAA); at 25 DAA (dough stage), abscisic acid (ABA) were maximum. At 35 DAA, all the endogenous hormonal level decreased and among the hormones, ABA was highest followed by IAA and GA 3 . Hexaploids recorded higher concentrations of endogenous hormones (13.38% IAA, 17.89% GA 3 , and 14.7% ABA) on fresh weight basis and resulted in higher seed weight (56.99 mg/grain) and grain growth rate (0.009 g/g/day) compared to tetraploids (49.08 mg/grain; 0.008 g/g/day) on dry weight basis by better mobilization of photosynthates during grain filling.

Raising yield potential of wheat. III. Optimizing partitioning to grain while maintaining lodging resistance

“…Several studies have characterized post-anthesis changes in hormone concentration in wheat grains [ABA, 1-aminocyclopropane-1-carboxylic acid (ACC)- Yang et al, 2006; ABA, gibberellin (GA), indole-3-acetic acid (IAA)- Gutam et al, 2008] but there is little information on the physiological roles of these changes in hormone content of developing wheat grains in response to environmental factors. Post-anthesis application of ABA and/or ethylene biosynthesis inhibitors directly to developing grains increased the ratio of ABA to ethylene and increased the grain-filling rate (Yang et al, 2006).…”

A promising growth promoting Meyerozyma caribbica from Solanum xanthocarpum alleviated stress in maize plants

“…Extraction and purification of plant hormones were analyzed by using HPLC according to the method of Kettner and Dörffling [47]. Fresh leaves (1 g) were ground at 4°C in 80% methanol with butylated hydroxy toluene (BHT) as an antioxidant (2 mg/100 ml) [48]. After 72 h extraction, the pooled extract was centrifuged at 3000 rpm and the supernatant was partitioned at pH 2.5–3 with ethyl acetate (1/4th volume of the extract).…”