Ecophysiological study of the impact of SiK^® fertilization on Castanea sativa Mill. seedling tolerance to high temperature

Abstract

The aim of this work was to evaluate the impact of Si fertilization on the resilience capacity of chestnut plants growing under high air temperatures and its recovery capacity after returning to optimal temperatures. Castanea sativa plants were supplied with 0, 5, 7.5, and 10 mM potassium silicate (SiK ®) and exposed for a month at each temperature, 25, 32, and 25°C. The results demonstrated that phytoliths were accumulated in the leaf tissues, both on the cell wall and xylem vessels, suggesting their role in the plant's tolerance to heat. Under high temperature, Si fertilization in chestnut plants increased the gas exchange and the photochemical efficiency of the PSII as the increase of 50% on performance index suggests. The presence of Si also induced higher contents of photosynthetic pigments and promoted a better adaptation of chloroplasts to high temperatures. The present study suggests that the application of Si may be used to enhance the high temperature tolerance of chestnut plants.

Influence of Climate Change on Chestnut Trees: A Review

“…Chestnut is a mesophilic species from warm temperate climates since the best conditions for its growth are moderate temperature and humidity [ 13 , 31 , 34 ] Additionally, chestnut is a moderate thermophilic species well adapted to ecosystems with an annual mean temperature ranging between 8–15 °C, and monthly mean temperatures during its vegetative cycle over 6–8 °C [ 13 , 30 , 31 , 37 ]. It tolerates a wide range of climatic conditions, varying from cool and wet conditions in the Atlantic bioclimatic region, to warm and dry conditions in the Mediterranean bioclimatic region [ 3 ].…”

“…This compound confers resistance to plants under biotic stress conditions through the combination of a physical and chemical defense system that improves resilience at morphological, physiological, and biochemical levels [ 80 ]. More specifically, silicon plays an important structural and protective role in the plant’s protection, with low energy costs due to the increase in the rigidity and abrasiveness (increase in the resistance of xylem vessels to drought and heat) of the vegetal tissues [ 37 ]. According to [ 79 ], plants treated with silicon showed better-recovering capacity when resubmitted to the new period of optimal temperature (25 °C) after the warm period (32 °C).…”

Characteristics of Leaf Stomata and Their Relationship with Photosynthesis in Saccharum officinarum Under Drought and Silicon Application

“…Numerous scientific reports published on insufficient water for plants have been shown to be compatible with upregulated leaf transpiration rates by Si amendment. 15 , 28 , 41 , 54 − 57 …”

“… 27 , 28 In particular, the connection of silicon with tolerance to environmental stresses has been studied extensively in various crops. 15 , 24 , 28 − 31 Silicon might be associated with physiologic and molecular mechanisms in plants 32 , 33 and potentially alleviates the detrimental impact of water stress, a severe abiotic stress.…”

Metalaxyl-M, phosphorous acid and potassium silicate applied as soil drenches show different chestnut seedling performance and protection against Phytophthora root rot

“…Other species of Phytophthora, such as P. cactorum and P. plurivora (formely P. citricola) may also damage chestnut trees, although with a lesser degree of aggressiveness (Akilli et al, 2012;Biocca et al, 1993;Vettraino et al, 2005). In Portugal, P. cinnamomi is the most frequently isolated species from the chestnut ecosystem and is, therefore, considered the predominant species in the development of ink disease (Carneiro-Carvalho et al, 2019;Fernandes, 1979;Gouveia, 2004). However, Jung, Jung, Cacciola, et al (2017b) described a new cryptic species of Phytophthora (P. castanetorum) for Portugal, in The Algarve and in the Natural Park of Serra da Estrela that can cause severe ink disease symptoms and may occur simultaneously with the predominant abovementioned species.…”