Soybean GmPHD-Type Transcription Regulators Improve Stress Tolerance in Transgenic Arabidopsis Plants

Abstract

BackgroundSoybean [Glycine max (L.) Merr.] is one of the most important crops for oil and protein resource. Improvement of stress tolerance will be beneficial for soybean seed production.Principal FindingsSix GmPHD genes encoding Alfin1-type PHD finger protein were identified and their expressions differentially responded to drought, salt, cold and ABA treatments. The six GmPHDs were nuclear proteins and showed ability to bind the cis-element “GTGGAG”. The N-terminal domain of GmPHD played a major role in DNA binding. Using a protoplast assay system, we find that GmPHD1 to GmPHD5 had transcriptional suppression activity whereas GmPHD6 did not have. In yeast assay, the GmPHD6 can form homodimer and heterodimer with the other GmPHDs except GmPHD2. The N-terminal plus the variable regions but not the PHD-finger is required for the dimerization. Transgenic Arabidopsis plants overexpressing the GmPHD2 showed salt tolerance when compared with the wild type plants. This tolerance was likely achieved by diminishing the oxidative stress through regulation of downstream genes.SignificanceThese results provide important clues for soybean stress tolerance through manipulation of PHD-type transcription regulator.

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

“…Five of these (GmPHD1 to GmPHD5) have transcriptional suppression activity and GmPHD2 improves stress tolerance. GmPHD6 does not have such transcriptional suppression activity; however, this protein can interact with other GmPHDs except GmPHD2, and the GmPHD6 gene can be induced by stresses (Wei et al, 2009). The GmPHD6 protein was pursued for its possible roles in stress response and the mechanism involved was further investigated.…”

“…GmPHD6 Interacts with LHP1-1 or LHP1-2 to Activate Gene Expression GmPHD6 has DNA binding ability and improves salt stress tolerance (Wei et al, 2009;Fig. 1); however, it does not have transcriptional activation and/or suppression ability (Wei et al, 2009).…”

“…1); however, it does not have transcriptional activation and/or suppression ability (Wei et al, 2009). It is possible that GmPHD6 may recruit some cofactors for regulation of downstream genes and affect stress responses.…”

“…Previously, we have characterized the six Alfin1-like proteins in soybean (Glycine max) and find that the N-terminal domain plays a major role in DNA binding. GmPHD1 to GmPHD5 have transcriptional suppression activity but GmPHD6 does not have this activity (Wei et al, 2009). The Alfin1-like proteins are usually associated with abiotic stress responses (Wu et al, 2011;Song et al, 2013;Wei et al, 2015).…”

Genetic, proteomic and metabolic analysis of the regulation of energy storage in rice seedlings in response to drought

“…Numerous genes, such as SINAGS1 [3], HARDY [4], and RWC3 [5], confer resistance to drought. Many attempts have been made to improve drought resistance in plants through gene transfer [6][7][8][9][10]. However, field tests of these transgenic plants have not shown better performance or crop yield [11][12][13].…”