Physiological seed quality evaluation and seedling Lipid and protein content of soybean (Glycine max (L.) Merrill), in the presence of rho-coumaric acid

The phenolic acids (PA), which have been widely studied by researchers due to their action upon seedlings germination and growth, as well as upon plan t metabolism, can affect the yield of the crops, resulting in damage to the agriculturists. The experiment carried out in this study aimed to evaluate the influence of rho -coumaric acid (rho -CA) on germination and vigor of soybean seeds and in the quantification of total lipids and total soluble p roteins of Embrapa-58 variety. The seeds were laid out on three sheets of t owel paper and submitted to different concentrations (0, 0.1, 1.0, 5.0 and 10.0 mM) of the PA. These sheets were then made into rolls and placed in a Mangelsdorf germinator at 25 degreesC for eight days. The seeds were evalua ted by three different means: a germination test, radicle and hypocotyl len gths, as well as their fresh and dry biomass. For the biochemistry evaluati ons the seeds were germinated for a seven day period and after that, the se edlings were dried at 80 degreesC, during 24 hr and, afterwards, the lipid content of cotyledons and proteins in the three components of seedlings wer e assessed. The results showed that there were no significant differences i n terms of cumulative seed germination in the presence of the compound stud ied, although a delay was observed in the germinative process. However, in the seed germination test a great reduction in normal seedlings was observe d. In relation to the growth evaluation of seedlings a great reduction in t he length of radicles was verified. As for the biomass evaluation, a decrea se of fresh and dry biomass, mainly of radicles was observed. In the bioche mistry evaluations an increase of lipids and protein content was found out in the presence of rho -CA. Although the action mechanisms of these alleloc hemicals are not completely elucidated, the results showed alterations not only in the seedlings morphology, especially in the roots, but also in the metabolism of proteins and in the mobilization of lipids.