Linking changes in chlorophyll a fluorescence with drought stress susceptibility in mung bean [Vigna radiata (L.) Wilczek]

Abstract

In the present study, the mung bean cv. NM-13-1 Tol was selected as drought-tolerant and NM-54 Sens as drought-sensitive. The effects of progressive drought (16 days) on the photosystem II (PSII) activity was assessed using OJIP and JIP-test in the selected two mung bean cultivars differing in drought tolerance. Drought stress reduced the relative water content to 70% (at threshold) and 62% (below the threshold) in cv. NM-13-1 Tol and NM-54 sens , respectively. The greater reduction in quantum yield of PSII in cv.NM-54 sens due to drought stress was due to PSII photodamage. Raw OJIP induction curves and F o and F m normalised curves showed that significant changes in fluorescence occurred at the O, J, I and P steps only in cv. NM-54 sens . Double normalised differential kinetics indicated adverse effects at the antennae, oxygenevolving complex and intersystem electron acceptors in cv.NM54 sens . Moreover, JIPtest analysis showed that drought stress caused a greater decrease in performance index (PI ABS ) in cv.NM-54 sens as compared to that in cv. NM-13-1 Tol , which is associated with an increase in V j , rate of accumulation of closed reaction centres (M o ), energy fluxes for absorption (ABS/RC), trapping (TR o /RC), electron transport (ET o / RC), and dissipation of absorbed energy as heat (DI o /RC). In conclusion, two-week drought stress reduced the RWC below the threshold in cv.NM54 sens , which resulted in damages at the donor and acceptor sides of PSII. However, cv.NM-13-1 Tol somehow maintained the RWC around the threshold and thus protected PSII. Of various JIP-test parameters, PI ABS , F v /F m , V j and M o are key indicators of drought stress tolerance in mung bean cultivars.

PSII photochemistry responses to drought stress in autochthonous and modern sweet cherry cultivars

“…The increase in WC at 3 and 5 DAS in autochthonous cultivar Crveni hrušt indicates the better acclimation of this cultivar to water stress conditions, probably because of better ability to mention water loss from the leaves. We presumed that higher water content in this cultivar was due to activation of some defense mechanisms and accumulation of some compounds, such as proline, causing a decrease of osmotic potential and increase leaf turgor (Bandurska and Jόźwiak 2010). Our results are consistent with other reports which presented that drought-tolerant plants have higher water content and photosynthetic efficiency (Kumar et al 2014, Braga et al 2020.…”

“…It is known that drought stress in plants disturbs the photosynthetic electron transport, leading to a decrease in photosynthesis and causing excessive production of ROS (Takahashi and Murata 2008). Oxidative injuries caused by drought stress resulted in lipid peroxidation and MDA content is used to examine the oxidative damage in the cell membranes (Bandurska and Jόźwiak 2010). Increases in the MDA content of the modern cultivar New Star suggest that drought stress induced oxidative damage of the membrane system in this cultivar.…”

Combinations of Blue and Red LEDs Increase the Morphophysiological Performance and Furanocoumarin Production of Brosimum gaudichaudii Trécul in vitro

“…The results clearly stated that the different spectra influenced the photosynthetic apparatus ( Figure 3A ). Changes in initial fluorescence (F O ) observed under red LEDs ( Figure 3B ), may be related to energy losses in the pigments of the PSII antenna complex (Rosa et al, 2018 ), which may be indicative of partial inhibition of the PSII reaction center, which in turn may have inhibited the flow of electrons from the primary quinone electron acceptor (Q A ) to the secondary quinone electron acceptor (Q B ), decreasing the efficiency of the energy captured in the PSII, indicating damage to the D 1 protein in the reaction center (Strasser et al, 2004 ; Bano et al, 2021 ). This decrease in photosynthetic efficiency may be related to a lower need for trapped energy to close the reaction centers, indicating that there was a reduction in primary photochemical activity (Kumar et al, 2020 ).…”

Polyphasic OKJIP Chlorophyll a Fluorescence Transient in a Landrace and a Commercial Cultivar of Sweet Pepper (Capsicum annuum, L.) under Long-Term Salt Stress

“…Detailed definitions and equations of raw and derived JIP test fluorescence parameters are reported in Table 1 (see also [ 11 ]). Authors have used JIP test to study the effects of various types of stress [ 17 ] Faseela at al.2020 [ 18 ], such as heat [ 13 , 19 ] drought [ 20 , 21 , 22 , 23 ], salinity [ 24 , 25 ], combined drought and salt stress [ 26 , 27 ] ozone [ 28 , 29 ], nutrient deficiency [ 30 , 31 ], toxic metals [ 10 ], or climate change [ 32 ].…”