Relationship between photochemical reflectance index and leaf ecophysiological and biochemical parameters under two different water statuses: towards a rapid and efficient correction method using real‐time measurements

Abstract

The use of the photochemical reflectance index (PRI) as a promising proxy of light use efficiency (LUE) has been extensively studied, and some issues have been identified, notably the sensitivity of PRI to leaf pigment composition and the variability in PRI response to LUE because of stress. In this study, we introduce a method that enables us to track the short-term PRI response to LUE changes because of photosynthetically active radiation (PAR) changes. The analysis of these short-term relationships between PRI and LUE throughout the growing season in two species (Quercus robur L. and Fagus sylvatica L.) under two different soil water statuses showed a clear change in PRI response to LUE, which is related to leaf pigment content. The use of an estimated or approximated PRI0, defined as the PRI of perfectly dark-adapted leaves, allowed us to separate the PRI variability due to leaf pigment content changes and the physiologically related PRI variability over both daily (PAR-related) and seasonal (soil water content-related) scales. The corrected PRI obtained by subtracting PRI0 from the PRI measurements showed a good correlation with the LUE over both of the species, soil water statuses and over the entire growing season.

Retrieval of the photochemical reflectance index for assessing xanthophyll cycle activity: a comparison of near-surface optical sensors

“…The physiological PRI responses reported here from the dark-to-light transition experiments are similar to those of others (Gamon et al, 1990(Gamon et al, , 1992Gamon and Berry, 2012;Hmimina et al, 2014). All species showed a decline in the PRI as plants were exposed to rapid increases in illumination, suggesting changes in the epoxidation state of the xanthophyll cycle in response to increased sun exposure (Demmig-Adams, 1990).…”

Potential of Photochemical Reflectance Index for Indicating Photochemistry and Light Use Efficiency in Leaves of European Beech and Norway Spruce Trees

“…This has been reported also for pine trees [15]. In accordance with work conducted on different plant species, the highest ∆PRI values have been observed in seedlings suffering from drought and exposed to high irradiance [23,24]. Observed stomata closure ( Figure 6C,D), photosynthetic downregulation ( Figure 6A,B), and extensive synthesis of carotenoids (Figure 3) constitute the basis for high NPQ ( Figure 5C,D) in many species during drought episodes [71].…”

“…Such PRI 0 determination is complicated under natural conditions for measurements under low sun elevations in the morning, however, due to the constraint created by the bidirectional reflectance distribution function. At this point, mathematical deconvolution of PRI 0 derived from early morning measurements of PRI under increasing PAR intensities as the intercept of the linear regressions of PRI versus PAR, proposed by Hmimina et al [24], seems a proper method for estimating PRI 0 . In this study the problems with PRI 0 estimation were reduced by measurement at a constant low irradiance level and constant (nadir) illumination geometry.…”

Connection of the Photochemical Reflectance Index (PRI) with the Photosystem II Quantum Yield and Nonphotochemical Quenching Can Be Dependent on Variations of Photosynthetic Parameters among Investigated Plants: A Meta-Analysis

“…P min and P max were calculated in each analyzed variant from literature data. P min of NPQ and P max of ∆F/F m ' and LUE showed the minimal level of photosynthetic stress among investigated plants, because the action of stressors increases nonphotochemical quenching and decreases the quantum yield of photosystem II [7,41,47,99] and light use efficiency [55,56]. Another parameter that was used was the difference between maximal and minimal values of NPQ, ∆F/F m ', and LUE (∆P abs = P max − P min ).…”

“…Connections between PRI and other photosynthetic parameters, including a quantum yield of photosystem II (∆F/F m ') [38,41,42,[45][46][47][48][49], photosynthetic light use efficiency (LUE) [3,48,[50][51][52][53][54][55], and net CO 2 uptake [47,[56][57][58][59], are actively being investigated. However, the results of these different works vary considerably, e.g., the linear correlation coefficients between PRI and NPQ can range from −0.90 [38,49,60] to +0.86 [41] in different investigations.…”