Natural defence systems II. Active and passive resistance

Natural plant defence systems can be active or passive depending on how they repel the symptoms of biotic or abiotic attacks.

The abiotic stress is due to environmental factors such as the coldthe droughtor heat. On the other hand, biotic stress is caused by organisms such as fungi, bacteria, viruses or insects.

Biotic → Living being

Abiotic → Inherent environment

In order to resist attacks, plants have different forms of resistance. If the plant activates extraordinary physical barriers such as thickening of cell barriers or exudation of chemicals such as terpenes, alkaloids or phenols, this is known as active resistance.

Passive forms of resistance are triggered after contact with stress. At that point the signals that are produced trigger resistance activators, also known as "resistance triggers".elicitors“

Active Resistance

Active resistance can be stimulated with different molecules.

• Silicon - Increases photosynthetic and enzymatic activity. Hardens the cuticle and increases resistance to salinity.
• Glycine Betanin - Osmoregulator that increases drought resistance.
• Amino acids - are the precursors of hormonal stress defence processes.
• Vitamin C - Antioxidant.
• Chitosan - Acts against biotic stress by inducing plant resistance to 'anthracnose', 'fusarium', 'sclerotinia'.
• BPCP (Growth Promoting Bacteria) - Enhance plant growth and protect against pathogens.
• Trichodermas y Mycorrhizae - Improve water and nutrient absorption, protect against soil pathogens.
• Algae - Incorporate hormones, are osmoregulators and increase bioavailability.

Passive Resistance

Following the encounter between the stress and the plant, or induction by elicitors external passive resistance is generated which are known as Acquired Systemic Resistance 'SAR' and Induced Systemic Resistance 'IRS'..

Systemic acquired resistance (SAR) is an active, systemic, broad-spectrum systemic, broad-spectrum, active defence response that is associated with a high expression of defence genes (Hammerschmidt 1999). defence genes (Hammerschmidt 1999). In most cases, SAR is equally effective against fungi, bacteria, viruses, or nematodesregardless of the inducing organism (Ryals of the inducing organism (Ryals et al. 1996).

The salicylic acid is the molecule that has shown the most evidence of being involved in SAR pathways (Mauch-Mani and Métraux 1998).

Thus, favouring the amount of acid salicylic acid in the plant, we will increase its defences against biotrophic and hemibiotrophic fungi.

"TRY EQUAL, incorporates in its formulation, a proportion of phenolic acids (a derivative of the salicylic acid) so that increases the plant's SAR; its defence against biotrophic and hemibiotrophic fungi.

Induced systemic resistance (ISR) generally develops through root colonisation by rhizobacteria. It is characteristically mediated by pathways that are sensitive to the jasmonic acid and the ethylene and independent of the salicylic acid (Pieterse and Van Loon 1999). The production of ethylene is influenced by other phytohormones such as abscisic acid.

Therefore, by increasing the amount of jasmonic acid and ethylene, we will increase the plant's defences against necrotrophic and necrotrophic and hemibiotrophic fungi.

If you need more information on how to activate the natural defence systems of your greens, tees or pitches, please contact us at info@tiloom.com.

At Tiloom we have the most advanced natural resistance promoter products.

Carlos Ortiz del Río, graduate in Economics and Business Studies. Since April 2002, Manager of TRY COMPANY ABONOS and Technical and Commercial Manager of all the company's liquid nutritional fertilisers.