Chlorophyll fluorescence as a tool for nutrient status identification in rapeseed plants

Abstract

In natural conditions, plants growth and development depends on environmental conditions, including the availability of micro- and macroelements in the soil. Nutrient status should thus be examined not by establishing the effects of single nutrient deficiencies on the physiological state of the plant but by combinations of them. Differences in the nutrient content significantly affect the photochemical process of photosynthesis therefore playing a crucial role in plants growth and development. In this work, an attempt was made to find a connection between element content in (i) different soils, (ii) plant leaves, grown on these soils and (iii) changes in selected chlorophyll a fluorescence parameters, in order to find a method for early detection of plant stress resulting from the combination of nutrient status in natural conditions. To achieve this goal, a mathematical procedure was used which combines principal component analysis (a tool for the reduction of data complexity), hierarchical k-means (a classification method) and a machine-learning method—super-organising maps. Differences in the mineral content of soil and plant leaves resulted in functional changes in the photosynthetic machinery that can be measured by chlorophyll a fluorescent signals. Five groups of patterns in the chlorophyll fluorescent parameters were established: the ‘no deficiency’, Fe-specific deficiency, slight, moderate and strong deficiency. Unfavourable development in groups with nutrient deficiency of any kind was reflected by a strong increase in F o and ΔV/Δt 0 and decline in φ Po, φ Eo δ Ro and φ Ro. The strong deficiency group showed the suboptimal development of the photosynthetic machinery, which affects both PSII and PSI. The nutrient-deficient groups also differed in antenna complex organisation. Thus, our work suggests that the chlorophyll fluorescent method combined with machine-learning methods can be highly informative and in some cases, it can replace much more expensive and time-consuming procedures such as chemometric analyses.Electronic supplementary materialThe online version of this article (10.1007/s11120-017-0467-7) contains supplementary material, which is available to authorized users.

Interplay of Calcium and Nitric Oxide in improvement of Growth and Arsenic-induced Toxicity in Mustard Seedlings

“…Moreover, the drop in OJIP transient curves was intense upon c-PTIO + l-NAME supplementation to As + Ca treated seedlings indicating that in absence of NO, the effect of As became more severe (even in presence of Ca 2+ ), which could be due to: (i) inhibition in electron transport rate on the donor side of PS II as reflected by decreased values for area over the fluorescence curve (Area), which consequently decreased the maximum quantum yield for primary photochemistry www.nature.com/scientificreports www.nature.com/scientificreports/ (that designates trapped exciton moves an electron into the ETC beyond Q A − ) and the quantum yield of electron transport (ФE o ) was detected ( Fig. 4b), which consequently declined the pool size of Q A − (acceptor side of the PS II 17,26,27 ); suggesting lethargic flow of electrons from PS II to PS I and restriction of Q A − reoxidation (Q A − -Q A ), which could be associated with poor diffusion of PQ across the thylakoid membranes 28 . Indeed, the higher F o / F m designates that Q A reduction rate was much higher than its reoxidation rate by Q B and PS I activity under As + Ca + c-PTIO + l-NAME treatment.…”

Growth, Fruit Yield, Photosynthetic Characteristics, and Leaf Microelement Concentration of Two Blueberry Cultivars under Different Long-Term Soil pH Treatments

“…By measuring these chlorophyll fluorescence indexes, we can quickly and nondestructively study the photosynthetic physiological status of plants. These represent new measurement and diagnosis technology in vivo [11,38]. The fluorescence parameters of the stress-tolerant cultivars of blueberry were higher or more stable than those of the sensitive cultivars under stressful environments, such as high temperature [39], aluminum exposure [40], ultraviolet radiation [41], and high pH [7].…”

In Situ Hyperspectral Remote Sensing for Monitoring of Alpine Trampled and Recultivated Species

“…Fluorescence is the quantity of absorbed light (quanta) leading to excitation of chlorophyll particles that have not been used in photosynthesis due to stressors [14]; both abiotic and biotic. Therefore, the measurement of chlorophyll fluorescence is believed to be the best photosynthesis efficiency index [15] for most species, i.e., not exposed to stressors. Optimal fluorescence (F v /F m ) rates are approximately 0.83 with adaptation to darkness [16,17].…”