The dynamics of phytate accumulation and water releasing during maize seed filling, I: The dynamics of accumulation of phytic phosphorus

Abstract

Phytic acid is a phosphorus compound with the widest prevalence in nature; it encompasses 60-80% of seed phosphorus. Phytic acid is considered as an antinutritive compound and it is indigestible by monogastric animals. The lowering of the phytic content in course of increasing of available, i.e. inorganic phosphorus in maize seed could be achieved through breeding of the present populations. Phosphorus metabolism in low-phytic genotypes differs during seed filling. The aim of this experiment was to determine the accumulation of inorganic and phytic phosphorus, as well as, of soluble proteins in seed of four populations and six ZP hybrids, including one potentially low phytic population. The synthesis of storage substances, such as phytate, was the most intensive during the first 30 days of seed filling, which was particularly expressed in hybrids. In seed of populations with a relatively low phytic P content the phytate accumulation lasted during the whole filling period. In accordance with the increase of the phytic P content, the contents of inorganic P and soluble proteins decreased, and this reduction reached its maximum 15-30 days after pollination. It is important to underline that the content of all three examined components was relatively uniform in hybrid seed, while non-uniformity at the level of populations, especially in the content of phytic P can serve as a source of favourable properties for breeders.

Fitinska kiselina je najrasprostranjenije jedinjenje koje sadrži fosfor, i to 60-80% ukupnog fosfora u semenu. Ona se smatra antinutritivnom supstancom, jer monogastrični organizmi ne mogu da je svare. Smanjenje sadržaja fitinskog na ime lako pristupačnog, tj. neorganskog fosfora u semenu kukuruza moguće je izvršiti selekcijom genotipova iz postojećih populacija. Kod nisko-fitinskih genotipova kukuruza metabolizam fosfornih jedinjenja je drugačiji prilikom nalivanja semena. Cilj ogleda je bio da se ispita dinamika nakupljanja neorganskog i fitinskog fosfora, kao i rastvorljivih proteina tokom nalivanja semena kod četiri populacije i šest ZP hibrida kukuruza, uključujući i jednu potencijalno nisko-fitinsku populaciju. Tokom prvih 30 dana nalivanja semena kukuruza sinteza skladišnih supstanci, kao što je fitat, bila je najintenzivnija, što je posebno bilo izraženo kod hibrida kukuruza. Kod populacija sa relativno niskim učešćem fitinskog fosfora sinteza fitata je trajala tokom čitavog perioda nalivanja. Srazmerno povećanju sadržaja fitinskog, došlo je do smanjenja sadržaja neorganskog fosfora i rastvorljivih proteina, ali je ono bilo najintenzivnije između 15. i 30. dana od oplodnje. Značajno je istaći da je kod hibrida bio prisutan ujednačen sadržaj sve tri ispitivane komponente, dok neujednačenost na nivou populacija, pogotovo u sadržaju fitinskog fosfora može poslužiti kao izvor pogodnih svojstava za selekcionare.