Participation of stem and ear photosynthesis in formation of the crop and its quality in wheat

FRC Kazan Scientific Center of RAS, Kazan Institute of Biochemistry and Biophysics, 420088 Kazan, Russia

^* Corresponding author: vichikov@bk.ru

Abstract

Photosynthesis of various organs and their contribution to formation of ear caryopsis were measured using¹⁴CO₂ labeled carbon in the phase of caryopsis formation of spring wheat plants (Moskovskaya-35). It turned out that inclusion of¹⁴C into amino acids is more than twice as high in photosynthesis of an ear. Among labeled low molecular weight compounds in caryopsis, during a short exposure (2 hours) after photosynthesis, the most of the labeled carbon in the¹⁴CO₂ was found from the photoassimilates of the flag leaf (70.4%); from the ear (55.8%), and the least – from the stem under the flag (41.5%). The difference in inclusion of¹⁴C into the caryopsis’ total proteins was observed only with a short exposure of the photosynthesizing organ (2 hours). Water-soluble proteins, as products of photosynthesis of the flag leaf, were synthesized for the most in the caryopsis (flag – 73.9%; stem – 46.4% and ear – 44.8%), and in the synthesis of complex proteins, which are soluble in alkali and Triton X-100, most of¹⁴C was from the products of photosynthesis of non-leaf organs (10.5; 21.5; 28.4 and 4.3; 12.5; 13.4), respectively.