Response of Photosynthetic Performance to Drought Duration and Re-Watering in Maize

Abstract

The drought tolerance and capacity to recover after drought are important for plant growth and yield. In this study, two maize lines with different drought resistance were used to investigate the effects of different drought durations and subsequent re-watering on photosynthetic capacity, electron transfer and energy distribution, and antioxidative defense mechanisms of maize. Under short drought, maize plants decreased stomatal conductance and photosynthetic electron transport rate, and increased NPQ (Non-photochemical quenching) to dissipate excess excitation energy in time and protect the photosynthetic apparatus. With the increased drought duration, NPQ, antioxidase activity, PItotal (total performance index), ∆I/Io, ψEo (quantum yield for electron transport), φEo (efficiency/probability that an electron moves further than QA−), δRo (efficiency/probability with which an electron from the intersystem electron carriers is transferred to reduce end electron acceptors at the PSI acceptor side) and φRo (the quantum yield for the reduction of the end electron acceptors at the PSI acceptor side) were significantly reduced, while Y(NO) (quantum yield of nonregulated energy dissipation) and MDA (malondialdehyde) began to quickly increase. The photosynthetic rate and capacity of photosynthetic electron transport could not recover to the level of the plants subjected to normal water status after re-watering. These findings indicated that long drought damaged the PSI (photosystem I) and PSII (photosystem II) reaction center and decreased the electron transfer efficiency, and this damage could not be recovered by re-watering. Different drought resistance and recovery levels of photosynthetic performance were achieved by different maize lines. Compared with D340, D1798Z had higher NPQ and antioxidase activity, which was able to maintain functionality for longer in response to progressive drought, and it could also recover at more severe drought after re-watering, which indicated its higher tolerance to drought. It was concluded that the capacity of the energy dissipation and antioxidant enzyme system is crucial to mitigate the effects caused by drought, and the capacity to recover after re-watering was dependent on the severity and persistence of drought, adaptability, and recovery differences of the maize lines. The results provide a profound insight to understand the maize functional traits’ responses to drought stresses and re-watering.

Comparative Study of Drought Stress Effects on Traditional and Modern Apple Cultivars

“…This was reflected in the lower level of the PI ( total ) in this cultivar. The effects of drought stress observed in parameters PI ( total ) and RE 0 /ET 0 are in accordance with a previous report of Jia et al [44] in drought-stressed maize plants. (F v /F m ) known as maximum quantum yield of PS II represent the efficiency of PSII primary photochemistry.…”

Analysis of Physiological Indicators Associated with Drought Tolerance in Wheat under Drought and Re-Watering Conditions

“…These results suggest that prolonged drought damages the reaction centers photosystem I (PSI) and photosystem II (PSII). This is consistent with the findings of previous studies [ 57 ]. After well−watered conditions were met, the drought−tolerant cultivar LH 22 recovered more than the drought−sensitive cultivar ZM 366.…”

The Photosynthetic Efficiency and Carbohydrates Responses of Six Edamame (Glycine max. L. Merrill) Cultivars under Drought Stress

“…In general, PIabs and PItotal were lower at pod filling compared to flowering, suggesting that the photosynthesis responses of edamame during drought stress are growth stage-specific. Jia et al [ 38 ] also found that PSI and PSII activities declined with drought stress duration in maize. A decline in PIabs at pod filling suggests an inactivation of the PSII reaction centers (RCs) [ 18 ].…”

“…A decline in PIabs at pod filling suggests an inactivation of the PSII reaction centers (RCs) [ 18 ]. Therefore, increased PIabs in AGS429 and UVE17 under drought stress shows that these cultivars may have maintained their PSII RCs and avoided photo-inhibition of both photosystems [ 38 ]. Although cultivars generally had higher PItotal under drought stress, AGS354 and UVE17 had a decrease in PItotal at flowering and pod filling, respectively.…”