Abstract
In the last two decades, global environmental change has increased abiotic stress on plants and severely affected crops. For example, drought stress is a serious abiotic stress that rapidly and substantially alters the morphological, physiological, and molecular responses of plants. In Arabidopsis, several drought-responsive genes have been identified; however, the underlying molecular mechanism of drought tolerance in plants remains largely unclear. Here, we report that the “domain of unknown function” novel gene DUF569 (AT1G69890) positively regulates drought stress in Arabidopsis. The Arabidopsis loss-of-function mutant atduf569 showed significant sensitivity to drought stress, i.e., severe wilting at the rosette-leaf stage after water was withheld for 3 days. Importantly, the mutant plant did not recover after rewatering, unlike wild-type (WT) plants. In addition, atduf569 plants showed significantly lower abscisic acid accumulation under optimal and drought-stress conditions, as well as significantly higher electrolyte leakage when compared with WT Col-0 plants. Spectrophotometric analyses also indicated a significantly lower accumulation of polyphenols, flavonoids, carotenoids, and chlorophylls in atduf569 mutant plants. Overall, our results suggest that novel DUF569 is a positive regulator of the response to drought in Arabidopsis.
Highlights
The life cycle and production of plants are strongly affected by exposure to harsh environmental conditions [1]
To examine the possible role of DUF569 in the drought stress response, we exposed 4-week-old WT-Col-0, atnced3 plants lacking the 9-cis-epoxycarotenoid dioxygenase (NCED3) gene that is essential for abscisic acid (ABA) biosynthesis during drought stress [54], atcat-2 lacking the cationic amino acid transporters (AtCAT2) gene [11], and atduf569 ecotypes to drought stress by withholding water for 10 days, as
We examined AtRGA1 expression, which was significantly increased in atduf569 plants at the third and seventh days of drought stress relative to the control plants, with similar expression patterns exhibited by the other genotypes
Summary
The life cycle and production of plants are strongly affected by exposure to harsh environmental conditions [1]. In Arabidopsis, the CAT gene family comprises CAT1, CAT2, and CAT3, which encode the CAT proteins Functional characterization of these genes has revealed that CAT2 is the most responsive; for example, the loss of function mutant atcat shows significantly reduced CAT activity compared with CAT1 and CAT3 mutants [11]. We examined the role of DUF569 (AT1G69890) in drought stress, demonstrating that during the rosette leaf stage following three days of water withdrawal, atduf569 plants typically showed severe wilting. After rewatering, these plants failed to recover. Our results suggest that DUF569 may play an essential role in controlling drought stress in Arabidopsis
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