Brassinosteroid phytochormones as regulators of plant growth and modulators of pesticide and fertilizer activity

Abstract

The mode of action of agrochemicals on plants implies the totality of their effect on plant metabolism, growth and development. The effects of different doses of 24-epibrassinolide (24-EBL) as a class of brassinosteroid phytohormones on growth and other physiological processes in maize plants during different development stages are reviewed in order to assess the influence of these agrochemicals on various factors determining the yield of maize as an important agricultural crop. In addition, several examples are given of the effects of these phytohormones on other crops, fruits and vegetables, in terms of their effect on yield, yield quality, and increase in crop resistance to some types of stress. Own results are discussed in the context of other literature data. Abbreviations: 24-EBL: 24-epibrassinolide; BRs: brassinosteroids; PCZ: propiconazole; Chl a: chlorophyl a; RFW (g g-1): relative fresh weight of different organs (R: radicle; P: plumule; RoS: rest of seed); TDW, TFW (g): total dry and fresh weight of plants; V root (ml): root volume; LMR, RMR, SMR (g g-1): relative dry weight of plant parts (leaves, roots, stem); dH (J mol-1 K-1): differential enthalpy of different parts (R: radicle; P: plumule; RoS: rest of seed) of 25 maize seedlings exposed to T(reatments) of different molar concentrations of 24-EBL; ΔG105 (J mol-1 K-1) differential Gibbs free energy of total maize plant and their parts (R: roots; L: leaves; S: stem) assesed at 105 0C; ZP434, ZP704, ZP505: maize hybrids; Fv/Fm, Fv/F0, FRS2, qP, NPQ, RFD730 (all in relative units), ETR (μmol electrons m-2 s-1): different Chl a fluorescence parameters; Pphy, Pi: phosphorus bond to phytic acid and free phosphorus available to many cellular biochemical reactions; GSH: reduced form of gluthathyone; K, Ca, Fe, Mg, Zn, Si: different chemical elements.

Način delovanja agrohemikalija na biljke podrazumeva ukupan uticaj na metabolizam, rast i razvoj biljaka. U tom smislu u ovom radu je prikazan efekat 24-epibrasinolida (24-EBL), kao klase fitohormona brasinosteroida, na rast i druge fiziološke procese u biljkama kukuruza u različitim dozama i u različitim razvojnim fazama, kako bi se procenio uticaj na razne faktore koji određuju prinos ovog važnog poljoprivrednog useva. Pored toga, dato je nekoliko primera efekata ovih fitohormona na druge useve, voće i povrće, u smislu njihovog uticaja na prinos, kvalitet prinosa i povećanje otpornosti useva na neke vrste stresa. Rezultati su diskutovani u odnosu na druge podatke iz literature.