An Ipomoea batatas Iron-Sulfur Cluster Scaffold Protein Gene, IbNFU1, Is Involved in Salt Tolerance

Abstract

Iron-sulfur cluster biosynthesis involving the nitrogen fixation (Nif) proteins has been proposed as a general mechanism acting in various organisms. NifU-like protein may play an important role in protecting plants against abiotic and biotic stresses. An iron-sulfur cluster scaffold protein gene, IbNFU1, was isolated from a salt-tolerant sweetpotato (Ipomoea batatas (L.) Lam.) line LM79 in our previous study, but its role in sweetpotato stress tolerance was not investigated. In the present study, the IbNFU1 gene was introduced into a salt-sensitive sweetpotato cv. Lizixiang to characterize its function in salt tolerance. The IbNFU1-overexpressing sweetpotato plants exhibited significantly higher salt tolerance compared with the wild-type. Proline and reduced ascorbate content were significantly increased, whereas malonaldehyde (MDA) content was significantly decreased in the transgenic plants. The activities of superoxide dismutase (SOD) and photosynthesis were significantly enhanced in the transgenic plants. H2O2 was also found to be significantly less accumulated in the transgenic plants than in the wild-type. Overexpression of IbNFU1 up-regulated pyrroline-5-carboxylate synthase (P5CS) and pyrroline-5-carboxylate reductase (P5CR) genes under salt stress. The systemic up-regulation of reactive oxygen species (ROS) scavenging genes was found in the transgenic plants under salt stress. These findings suggest that IbNFU1gene is involved in sweetpotato salt tolerance and enhances salt tolerance of the transgenic sweetpotato plants by regulating osmotic balance, protecting membrane integrity and photosynthesis and activating ROS scavenging system.

A myo‐inositol‐1‐phosphate synthase gene, IbMIPS1, enhances salt and drought tolerance and stem nematode resistance in transgenic sweet potato

“…In addition, the systematic up‐regulation of ROS‐scavenging genes was found in the transgenic plants under salt and drought stresses (Figure S8). Our results support that more proline accumulation stimulates ROS‐scavenging system, which leads to the improved salt and drought tolerance in the IbMIPS1 ‐overexpressing sweet potato plants (Liu et al ., ,b).…”

“…The BADH gene from spinach improved tolerance to salt, MV‐mediated oxidative and low temperature stresses in transgenic sweet potato (Fan et al ., ). Overexpression of the genes, IbOr , IbLCY‐ ε, IbNFU1 , IbP5CR , IbMas and IbSIMT1 , from sweet potato enhanced salt tolerance of this crop (Kim et al ., ,b; Liu et al ., ,b,c, ; Wang et al ., ).…”

Transcript profile analysis reveals important roles of jasmonic acid signalling pathway in the response of sweet potato to salt stress

“…Plant roots alter their developmental process to rapidly adapt to salt stress. The salt tolerance of sweet potato is improved through increasing betaine, proline and ABA contents, activating ROS scavenging and enhancing myo-inositol biosynthesis, photosynthesis and ion homoestasis29303132454647484950.…”

IbSIMT1, a novel salt-induced methyltransferase gene from Ipomoea batatas, is involved in salt tolerance

“…The overexpression of IbOr and IbLCY-e genes increased carotenoid accumulation and salt tolerance in transgenic sweetpotato calluses (Kim et al 2013a, b). Wang et al (2013a) isolated IbNFU1 gene from sweetpotato and Liu et al (2014b) found this gene was involved in salt tolerance of sweetpotato. Liu et al (2014a) cloned IbP5CR gene from sweetpotato and the IbP5CR-overexpressing sweetpotato plants exhibited higher salt tolerance.…”