Crosstalk between Nutrient Signalling Pathways and Immune Responses in Rice

Abstract

Rice is a staple food for more than half of the global population. Rice production is, however, severely affected by biotic and abiotic stresses. Fertilisers and pesticides are widely used in rice farming to maintain optimal yield and to prevent losses caused by environmental stress. However, the indiscriminate use of agrochemicals has adverse effects on the environment and human health. Stress caused by nutrient excess or deficiency has an impact on plant disease resistance. The interference of plant responses induced by nutrient stress can result in a positive or negative impact on resistance to pathogen infection. In this review, we explore the effects of combined stresses in rice, focusing on nutrient stress, such as nitrogen and phosphorous supply, and infection by fungal pathogen Magnaporthe oryzae, the causal agent of rice blast disease. Crosstalk between nutrient stress-induced and pathogen-induced signalling pathways in rice is discussed, as well, with particular emphasis on regulatory microRNAs. Understanding the interconnected regulations between nutrient stress and disease resistance will lay a foundation for rationally optimising fertiliser and pesticide use in rice production.

Yield, Grain Quality, and Starch Physicochemical Properties of 2 Elite Thai Rice Cultivars Grown under Varying Production Systems and Soil Characteristics

“…The results of amylopectin fine structure of starches isolated from the two rice cultivars revealed differences in CLD of amylopectin branches between the net-house pot and open-field production systems (Table 5). Generally, amylopectin branch chains are compartmentalized into four different chain types including A chains (DP 612), B1 chains (DP 13-24), B2 chains (DP [25][26][27][28][29][30][31][32][33][34][35][36], and B3+ chains (DP ≥ 37) [9,48]. Here, the sensitivity of the HPAEC-PAD system allowed the resolve of glucans with DP ≤ 56.…”

“…Overabundant N could affect the mobility of Fe in soil, while excess K increased the root oxidizing power of rice, together resulting in oxidation of Fe 2+ to Fe 3+ , which prevented it from being taken up by the rice root [34]. Fe-deficiency in turn could result in chlorophyll shortage in photosynthetic tissues, reduced photosynthesis, decreased biomass production, which eventually hinder plant development and yield [35]. Fe also plays an important role in a number of plant cellular processes, and acts as a cofactor of several enzymes necessary for a wide range of biological functions [35].…”

“…Fe-deficiency in turn could result in chlorophyll shortage in photosynthetic tissues, reduced photosynthesis, decreased biomass production, which eventually hinder plant development and yield [35]. Fe also plays an important role in a number of plant cellular processes, and acts as a cofactor of several enzymes necessary for a wide range of biological functions [35]. In addition to the existence of soil nutrient, other factors such as light intensity within rice cultivation location could influence yield and grain quality of rice [74][75][76], by which the traditional open-field system provided higher light intensity than the inside of net-house system [76].…”

“…Not only the nutrient deficiency condition but also the nutrient toxicity condition owing to excessive supplies of nutrients can enhance the invasion of pathogen and insects [32,33]. The deficiency of micronutrients (e.g., iron (Fe)) also affected numerous metabolic processes such as DNA synthesis, respiration, and photosynthesis [34,35]. As a result, the rice plant exposed to nutrient imbalance typically shows characteristic symptoms, such as poor root formation, thinner stems, folded leaves, pale green and dark brown necrotic spots, and yellow, burnt-orange and dying leaves, which ultimately lead to the retardation of normal growth and the decreases of tillering, panicle number, and yield ability of the rice [32][33][34][35][36][37].…”

“…The deficiency of micronutrients (e.g., iron (Fe)) also affected numerous metabolic processes such as DNA synthesis, respiration, and photosynthesis [34,35]. As a result, the rice plant exposed to nutrient imbalance typically shows characteristic symptoms, such as poor root formation, thinner stems, folded leaves, pale green and dark brown necrotic spots, and yellow, burnt-orange and dying leaves, which ultimately lead to the retardation of normal growth and the decreases of tillering, panicle number, and yield ability of the rice [32][33][34][35][36][37]. For instance, nitrogen and phosphorous deficiency in soil can cause the decreases of rice photosynthesis, growth, development, yield, and grain storage product compositions (e.g., amylose and protein contents) [30,[37][38][39].…”