Soybean miR172a Improves Salt Tolerance and Can Function as a Long-Distance Signal

Abstract

Soybean is an important crop for oil and protein resources but its growth and development may encounter various abiotic stresses, including high salinity, that can hinder soybean production. Manipulation of soybean stress tolerance requires a thorough understanding of the mechanisms underlying plant response to stresses. Evolutionarily, plants have developed multiple gene regulatory mechanisms to adjust cellular activities for better survival under stress conditions, and one of these is microRNA (miRNA)-mediated gene silencing (Zhang, 2015). Many conserved and novel miRNAs have been identified in different organs of soybean and in different processes during soybean development (Song et al., 2011). However, these soybean miRNAs were seldom studied in stress response. Previously, we have identified multiple stressresponsive transcription factor genes from soybean and analyzed their functions in stress response (Wei et al., 2009; Wang et al., 2015). Now we intend to explore the role of miRNAs in the regulation of soybean response to stresses. Among our previously identified miRNAs from soybean (Song et al., 2011), the gma-miR172a can be induced by salt and other stresses, and so was selected for further investigation.

Identification and expression analysis of miRNAs and elucidation of their role in salt tolerance in rice varieties susceptible and tolerant to salinity

“…Similar to TCP, the target of miR172a, AP2/EREBP domain protein SSAC1, is beneficial to plant at low level with regard to salt tolerance, as it functions as transcriptional repressor [65]. The overexpression of miR172a in fact improves salt tolerance in soybean [65]. The members of the family miR172 have also been found to be salt responsive in the wild rice O. coarctata and the African rice O. glaberrima [39,55], similar to this study.…”

“…Low level of TCP on the other hand increases cell proliferation [63,64], and hence decrease in its level because of salt-induced upregulation of miR319a might be helpful for the plant to maintain cell division and cell growth under the short period of salt stress condition. Similar to TCP, the target of miR172a, AP2/EREBP domain protein SSAC1, is beneficial to plant at low level with regard to salt tolerance, as it functions as transcriptional repressor [65]. The overexpression of miR172a in fact improves salt tolerance in soybean [65].…”

A Histone Code Reader and a Transcriptional Activator Interact to Regulate Genes for Salt Tolerance

“…Our findings suggest that overexpressing GmPHD6 in hairy roots may affect strigolactone synthesis and enhance salt tolerance in the aerial parts of soybean through promoting stomatal closure and maintaining water content. Other factors may also be involved in the stress tolerance of the soybean aerial parts (Pan et al, 2016).…”

Genome-Wide Analysis of the Glucose-6-Phosphate Dehydrogenase Family in Soybean and Functional Identification of GmG6PDH2 Involvement in Salt Stress

“…Soybean plants infected with the A. rhizogenes strain K599 were considered as control hairy roots. The transgenic lines were screened by PCR amplification and enzyme activity assay as described (Pan et al, 2016), and the non-transgenic hair roots were removed from the seedlings. Transgenic lines with similarlength hairy roots were selected and treated with 1/2 Hoagland solution containing 0 or 100 mM NaCl for 5 days, respectively.…”