Early-Stage Detection of Biotic and Abiotic Stress on Plants by Chlorophyll Fluorescence Imaging Analysis

Abstract

Most agricultural land, as a result of climate change, experiences severe stress that significantly reduces agricultural yields. Crop sensing by imaging techniques allows early-stage detection of biotic or abiotic stress to avoid damage and significant yield losses. Among the top certified imaging techniques for plant stress detection is chlorophyll a fluorescence imaging, which can evaluate spatiotemporal leaf changes, permitting the pre-symptomatic monitoring of plant physiological status long before any visible symptoms develop, allowing for high-throughput assessment. Here, we review different examples of how chlorophyll a fluorescence imaging analysis can be used to evaluate biotic and abiotic stress. Chlorophyll a is able to detect biotic stress as early as 15 min after Spodoptera exigua feeding, or 30 min after Botrytis cinerea application on tomato plants, or on the onset of water-deficit stress, and thus has potential for early stress detection. Chlorophyll fluorescence (ChlF) analysis is a rapid, non-invasive, easy to perform, low-cost, and highly sensitive method that can estimate photosynthetic performance and detect the influence of diverse stresses on plants. In terms of ChlF parameters, the fraction of open photosystem II (PSII) reaction centers (qp) can be used for early stress detection, since it has been found in many recent studies to be the most accurate and appropriate indicator for ChlF-based screening of the impact of environmental stress on plants.

Changes in Biologically Active Compounds in Pinus sylvestris Needles after Lymantria monacha Outbreaks and Treatment with Foray 76B

“…Reduced levels of these chlorophylls observed in the needle samples of damaged pine plots potentially signify persistent biotic stress and a deteriorating state of the damaged trees. It is acknowledged that insect herbivory adversely affects the photosynthesis process through the regulation of gene expression associated with photosynthesis [ 56 ]. Among the methods for rapidly detecting plant stress, the fluorescence imaging of Chl a exhibits significant potential, as it enables the assessment of plant physiological status long before visible symptoms manifest [ 56 ].…”

“…It is acknowledged that insect herbivory adversely affects the photosynthesis process through the regulation of gene expression associated with photosynthesis [ 56 ]. Among the methods for rapidly detecting plant stress, the fluorescence imaging of Chl a exhibits significant potential, as it enables the assessment of plant physiological status long before visible symptoms manifest [ 56 ]. Meanwhile, the concentrations of these photosynthetic pigments increased in the needles of damaged trees in the following year, which is important for faster forest stand recovery after such outbreaks [ 56 , 57 ].…”

“…Among the methods for rapidly detecting plant stress, the fluorescence imaging of Chl a exhibits significant potential, as it enables the assessment of plant physiological status long before visible symptoms manifest [ 56 ]. Meanwhile, the concentrations of these photosynthetic pigments increased in the needles of damaged trees in the following year, which is important for faster forest stand recovery after such outbreaks [ 56 , 57 ]. The results of our study also revealed that the concentrations of Chl a, Chl b, and Caro increased in the needles of P. sylvestris in Foray 76B treated areas in the following year after the treatment, which might be influenced by Bacillus thuringiensis subspecies kurstaki Strain (Btk) (Foray 76B main component) [ 58 , 59 ].…”

Comparative Phytotoxicity of Metallic Elements on Duckweed Lemna gibba L. Using Growth- and Chlorophyll Fluorescence Induction-Based Endpoints

“…Furthermore, toxicological studies also incorporated additional test endpoints, such as chlorophyll content [ 10 , 13 , 14 ], enzyme activities [ 15 , 16 ], colony size [ 17 , 18 ] and root length [ 19 , 20 ]. More recently, as an emerging non-invasive technique, the chlorophyll fluorescence (ChlF) induction method has also been increasingly utilized in various plant- and algae-based ecotoxicological studies [ 21 , 22 , 23 ].…”

Genetic parameters and responses associated with high temperature in potato wild relatives.

“…Understanding the genetic basis of these responses is crucial for developing strategies to enhance heat tolerance in potato crops. Gas exchange, through stomatal regulation, ensures the uptake of carbon dioxide essential for photosynthesis while facilitating the release of oxygen (Harrison et al 2020). This process supports the production of energy and vital compounds required for growth and development.…”