Biostimulants isolated or integrated with paclobutrazol as tomato development triggering factors

Abstract

Plant biostimulants are substances with different chemistry or biological composition whose, when applied to plants, can favour their development mainly by enhance nutrient uptake or nutrition efficiency and also can alter plant hormonal balance. Paclobutrazol (PBZ) is a retardant plant growth regulator which promotes reduction on stem internodes culminating in shorter plants. The integration of both, biostimulants and PBZ, can lead better development of plants by at same time favour the nutrition performance of shorter plants. Although some farmers already have used these substances in crop field, alone or in combination, there is a great lack of scientific studies to verify the real efficiency of the biostimulants available in market. The aim of this study was to study the effect of different biostimulants on the morphometrical and physiological aspects of tomato when applied in combination or not with paclobutrazol in Solanum lycopersicum L., hybrid H9553. The biostimulants used were Stimulate®, Serenade®, EnerVig®, Px-Fertil®, Vorax®, Liqui-plex® and DuoOrgano+®. PBZ reduced plant height and, unlike expected, no one of the biostimulants favoured volume increase or dry mass of roots. However, all biostimulants favoured the accumulation of leaf dry mass, with no increase in the number of leaves or net photosynthetic rate per specific leaf area. When isolated, or in interaction with biostimulants, the PBZ generated stimulatory or inhibitory effect on expression of the parameters evaluated, depending on the organ and its age, and acted in synergism or antagonism with the biostimulants, depending on the substance in question.

Growth and physiology of ornamental sunflower under salinity in function of paclobutrazol application methods

“…The higher net photosynthesis promoted by the application of PBZ via soil may be related to the more efficient action of this growth regulator on the xylem and phloem vessels (Jaleel et al, 2007), favoring greater availability of water and nutrients to the roots for the aerial part, which contributed to photosynthesis rate, since PBZ interferes in the source-sink relationship (Silva et al, 2020). PBZ induced improvement in gas exchange was also observed in plants of Catharanthus roseus (Jaleel et al, 2007), Paeonia lactiflora (Xia et al, 2018), Solanum lycopersicum (Silva et al, 2020), and forest species (Cregg & Ellison-Smith, 2020) in the absence of stress, besides Chenopodium quinoa under salt stress (Waqas et al, 2017).…”

“…PBZ also operate in the absence of stress as in Catharanthus roseus, which increased the photosynthetic rate (Jaleel et al, 2007), in Solanum lycopersicum increased stomatal conductance (Silva et al, 2020) and sunflower decreased plant height without affecting biomass production (Barbosa et al, 2009;Brito et al, 2016). Despite these reports of PBZ on sunflower, the effects of different application methods are not known under salt stress conditions.…”

Metabolomic analysis reveals stress tolerance mechanisms in common bean (Phaseolus vulgaris L.) related to treatment with a biostimulant obtained from Corynebacterium glutamicum

“…Besides, among a series of biostimulants evaluated for the development of S. lycopersicum L., only the plants subjected to the application of Vorax TM showed an increase in the dry mass of leaves compared to the control plants. 23 However, modulations in plant metabolism due to Vorax TM treatment were not evaluated yet. Given the importance of knowing the modes of action of biostimulants and their effects on plants, this study is the first to assess the specialized metabolism of a crop ( P. vulgaris ) after treatment with Vorax TM .…”

“…Among amino acids, the highest percentage is l -glutamic acid (25.6%). Although some studies demonstrate the positive effect of Vorax TM treatment in several crops, 22,23 the effects of this biostimulant in the plant metabolome remained unknown.…”