Chapter

Physiological effects related to brassinosteroid application in plants

DOI: 10.1007/978-94-007-0189-2_7

ABSTRACT Brassinosteroids are plant hormones whose functions have been discovered in the past years. In order to confirm scientifically
the biological effects caused exclusively by these compounds, different tools can be used, such as BRdeficient or BR-perceptive
mutants, molecular studies, biological assays, application of brassinosteroid biosynthesis inhibitors, endogenous quantification
and exogenous application. This work aims at relating the physiological effects in plants when exposed to different dosages
and analogues of brassinosteroids during different phases of development (germination, flowering, fructification) and when
submitted to biotic and abiotic stress (pathogens, water stress, saline stress, hypoxia, temperature, heavy metals and pesticides)
as well as the particularities related to tropisms, circadian rhythms and interactions with other plant hormones. The use
of brassinosteroids with the objective of increasing crop yield in the field and to improve the quality of the seedlings has
also received attention in recent papers. The main objective of this chapter is to discuss the physiological effects that
occur in cells, tissue or whole plants when submitted to brassinosteroid applications, taking into account the possible mechanism
of action of these compounds and their practical use in agriculture, describing the analogues and the dosages used in field
and laboratory experiments during the last 10 years.

Key wordsbrassinosteroid concentration-brassinosteroid analogue-germination-flowering-plant tissue culture-plant stress

7 Followers
 · 
623 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Brassinosteroids (BRs) are polyhydroxylated steroidal plant hormones that play pivotal role in the regulation of various plant growth and development processes. BR biosynthetic or signaling mutants clearly indicate that these plant steroids are essential for regulating a variety of physiological processes including cellular expansion and proliferation, vascular differentiation, male fertility, timing senescence, and leaf development. Moreover, BRs regulate the expression of hundreds of genes, affect the activity of numerous metabolic pathways, and help to control overall developmental programs leading to morphogenesis. On the other hand, the potential application of BRs in agriculture to improve growth and yield under various stress conditions including drought, salinity, extreme temperatures, and heavy metal (Cd, Cu, Al, and Ni) toxicity, is of immense significance as these stresses severely hamper the normal metabolism of plants. Keeping in mind the multifaceted role of BRs, an attempt has been made to cover the various aspects mediated by BRs particularly under stress conditions and a possible mechanism of action of BRs has also been suggested.
    Biologia Plantarum 03/2014; 58(1). DOI:10.1007/s10535-013-0374-5 · 1.74 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Salt stress is among the major abiotic stresses that adversely affect the global crop production and its adverse impacts are getting more serious in the regions where saline water is used for irrigation. It induces reactive oxygen species, alters the activity of antioxidant system and adversely affects the process of photosynthesis. Various strategies have been employed to mitigate the deleterious effects of salt stress. Presently, the recommended strategies to overcome the adverse effects of salt stress include the use of tolerant cultivars, ameliorative water management and diverse cultural practices. However, none of these approaches have been found to be fully effective under salt stress conditions. An alternative and technically simpler approach to induce salt stress tolerance is the exogenous application of plant growth regulators (PGRs). This technique has gained significant importance during the past decade. PGRs have been implicated to regulate a wide range of metabolic and physiological activities in plants, ranging from cell division and organogenesis to protection against biotic and abiotic stresses. One of the important factors for enhanced plant productivity by PGRs is their efficiency to overcome the salt-induced stress conditions. Recent findings on the effects of brassinosteroids and polyamines on the salt stress tolerance of crops open new avenues to address the salinity problems. This review enlightens the role of brassinosteroids and polyamines in different plant processes like their role in regulation of photosynthesis, antioxidant systems and other related aspects, thereby improving overall performance of plants.
    Acta Physiologiae Plantarum 07/2013; 35(7). DOI:10.1007/s11738-013-1263-4 · 1.52 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The grape berries of two varieties, Yan73 (Vitis vinifera L.) and Cabernet Sauvignon (CS) (Vitis vinifera L.) were treated with 0.40 mg/L 24-epibrassinolide (EBR), 1.00 mg/L brassinazole (Brz), and deionized water (control), at the veraison period. The EBR treatment significantly increased total phenolic content (TPC), total tannin content (TTC) and total anthocyanin content (TAC) of Yan73 and CS wines, whereas Brz treatment decreased TPC, total flavonoid content (TFC), TAC in the two wines. Moreover, the content of most of the phenolic compounds identified by HPLC-DAD/ESI-MS in EBR-treated wines was significantly higher than that in control. The antioxidant capacities, which determined using DPPH, ABTS and HRSA methods, of the wines were increased by EBR treatment as well. There was a good correlation between the antioxidant capacity and phenolic content. The results demonstrated that EBR could enhance the phenolic compounds and antioxidant capacity of Yan73 and CS wines, but the effects may vary by different cultivars.
    Molecules 07/2014; 19(7):10189-10207. DOI:10.3390/molecules190710189 · 2.10 Impact Factor