Paenibacillus polymyxa BFKC01 enhances plant iron absorption via improved root systems and activated iron acquisition mechanisms

Improved iron acquisition ofAstragalus sinicusunder low iron-availability conditions by soil-borne bacteriaBurkholderia cepacia

“…Many crop plants such as barely and peanut often exhibit Fe deficiency-induced leaf chlorosis under alkaline conditions (Takahashi et al 2001;Xiong et al 2013). Calcareous soils account for about a third of the earth's crust, Fe deficiency thus becomes one of major abiotic stresses that seriously affect plant growth and development, crop yield and quality (Takahashi et al 2001;Xiong et al 2013;Zhou et al 2016). Fe deficiency is also one of the most wide-ranging nutrient deficiency in human dietary, which causes adverse impacts on approximate 2 billion people health, and even 0.8 million death annually (Murgia et al 2012).…”

“…Moreover, these individual components of Fe acquisition machines in plants are finely controlled by Fe deficiencyinduced transcription factors (FIT) such as FIT1, bHLH38 and bHLH39 (Wang et al 2007;Yuan et al 2008). However, plants equipped with the Fe reduction-based mechanism often display typical symptoms of Fe deficiency under alkaline conditions (Xiong et al 2013;Zhou et al 2016). The protons released by Fe-deficient plants are mostly buffered by high alkaline pH conditions, and the FCR activities are also seriously depressed (Ohwaki and Sugahara 1997), indicating that the Fe reduction-based mechanism is readily impeded in the strategy I plants grown in alkaline soils.…”

“…Recently, many studies have indicated that plant roots can secrete several metabolites to attract colonization of diverse species of soil microbes in rhizosperic soils, and some of which can promote plant growth and enhance the tolerance of host plants to abiotic and biotic stresses (Dey et al 2004;Mishra et al 2014;Zhou et al 2016;Zhou et al 2017). These beneficial soil microbes are generally called as plant growth promoting rhizobacteria (PGPR).…”

“…These beneficial soil microbes are generally called as plant growth promoting rhizobacteria (PGPR). Importantly, some PGPR strains have great potential to improve Fe absorption in plants (Pii et al 2015(Pii et al , 2016Zhou et al 2016). Bacillus subtilis GB03 activates the Fe acquisition machinery in Arabidopsis and cassava (Manihot esculenta) plants (Zhang et al 2009;Freitas et al 2015).…”

“…Bacillus subtilis GB03 activates the Fe acquisition machinery in Arabidopsis and cassava (Manihot esculenta) plants (Zhang et al 2009;Freitas et al 2015). Zhou et al (2016) have reported that the inoculation with Paenibacillus polymyxa BFKC01 increases Fe content in Arabidopsis plants under alkaline conditions. Thus, application of soil beneficial bacteria will become a most promising path to enhance plant's Fe acquisition under low Fe-availability conditions.…”