Abstract
Most crop plants are exposed to intermittent drought periods. To cope with these continuous changes, plants need strategies to prevent themselves from exhaustive adjustment maneuvers. Drought stress recovery has been shown to be an active process, possibly involved in a drought memory effect allowing plants to better cope with recurrent aridity. An integrated understanding of the molecular processes of enhanced drought tolerance is required to tailor key networks for improved crop protection. During summer, prolonged periods of drought are the major reason for economic yield losses of sugar beet (Beta vulgaris) in Europe. A drought stress and recovery time course experiment was carried out under controlled environmental conditions. In order to find regulatory key mechanisms enabling plants to rapidly react to periodic stress events, beets were either subjected to 11 days of progressive drought, or were drought stressed for 9 days followed by gradual rewatering for 14 days. Based on physiological measurements of leaf water relations and changes in different stress indicators, plants experienced a switch from moderate to severe water stress between day 9 and 11 of drought. The leaf proteome was analyzed, revealing induced protein pre-adjustment (prior to severe stress) and putative stress endurance processes. Three key protein targets, regulatory relevant during drought stress and with lingering levels of abundance upon rewatering were further exploited through their transcript performance. These three targets consist of a jasmonate induced, a salt-stress enhanced and a phosphatidylethanolamine-binding protein. The data demonstrate delayed protein responses to stress compared to their transcripts and indicate that the lingering mechanism is post-transcriptionally regulated. A set of lingering proteins is discussed with respect to a possible involvement in drought stress acclimation and memory effects.
Highlights
Drought stress is one of the main constraints to crop production worldwide
On day 9 of the drought stress (D9), osmotic potential and relative water content were significantly lower, and electrolyte leakage was significantly higher than the controls
All three parameters started to recover immediately upon rewatering (DR11), even though they all returned to control levels only on day DR17 (RWC, osmotic potential (OP)) or DR19 (EL)
Summary
Drought stress is one of the main constraints to crop production worldwide. Different from arid climates, central Europe faces increasing occurrence of intermittent drought periods, in late summer, and during the early development of crops. Several studies have shown that plants can respond differently to repeated periods of stress and that the first stress period might trigger maintained metabolic and epigenetic rearrangements commonly known as “stress memory” (stress imprint) (Bruce et al, 2007; Ding et al, 2012) Such imprints include the accumulation of protective metabolites (Bhargava and Kshitija, 2013), signaling proteins or transcription factors (Conrath et al, 2006; Ramírez et al, 2015), the phosphorylation of key regulatory proteins such as MAPKs, chromatin marks or epigenetic modifications (Ding et al, 2012; Kinoshita and Seki, 2014), all of which may render the plant more “prepared” and more resistant if the stress recurs. Other studies indicate distinct dynamics and independent regulation of recovery after drought stress (Lehmann et al, 2012; Lyon et al, 2016; Wedeking et al, 2017, 2018)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
