Abstract
BackgroundPlant roots are highly plastic to high salinity. However, the molecular mechanism by which root developmental plasticity is regulated remains largely unknown. Previously we reported that miR172c-NNC1 module plays a key role in soybean-rhizobial symbiosis. The fact that the miR172c promoter contains several stress-related cis elements indicates that miR172c may have a role in root response to abiotic stress.ResultsHere we showed that miR172c is greatly induced by salt stress in soybean. Overexpression of miR172c and knockdown of miR172c activity resulted in substantially increased and reduced root sensitivity to salt stress, respectively. Furthermore, we show that the target gene NNC1 (Nodule Number Control 1) of miR172c was downregulated by salt stress. The transgenic roots overexpressing or knocking down NNC1 expression also exhibited the altered root sensitivity to salt stress.ConclusionThe study reveals the crucial role of miR172c-NNC1 module in root stress tolerance to salt stress in soybean.
Highlights
Plant roots are highly plastic to high salinity
Soybean miR172c is induced by salt stress Analysis of the miR172c promoter reveals manifold cisregulatory elements related to early responses to dehydration and abscisic acid (ABA), including ACGTATERD1, ABRELATERD1, DPBFCOREDCDC, MYB2AT and MYBCORE (Fig. 1a)
When the soybean seedlings were subjected to salt stress on B5 medium containing 75 mM NaCl, miR172c was rapidly induced in roots and the expression levels of miR172c were continuously elevated during the prolonged exposure treatment (Fig. 1b)
Summary
Plant roots are highly plastic to high salinity. the molecular mechanism by which root developmental plasticity is regulated remains largely unknown. Several genes that mediate soybean plant responses to salt stress have been identified. These soybean genes are involved in various biological processes [3]. GmWRKY27 physically interacts with GmMYB172 to repress the expression of GmNAC29 that modulates plant tolerance to salt and drought stresses in soybean [9]. These results highlight the pivotal roles of Sahito et al BMC Plant Biology (2017) 17:229 the transcription factor-mediated reprogramming in soybean adaptation to salt stress. The upstream regulators of these salt stressrelated transcription factors in soybean remains elusive
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
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 call
