Elymus dahuricus H+-PPase EdVP1 enhances potassium uptake and utilization of wheat through the development of root system

Abstract

We investigated the differences of K acquisition and utilization, morphological and physiological characteristics of roots and grain yield between Elymus dahuricus H + -PPase (EdVP1) transgenic wheat and wild type wheat under low K stress. The results showed that, the grain yield and K economic utilization index (KUI-E) in wild type wheat were only 61.14% and 50.20% of those in EdVP1 transgenic wheat. EdVP1 increased the free IAA accumulations in roots, which may play a key role in the development of root system. The total root length, total root surface area, root tips and total root volume in transgenic wheat were 2.26, 2.23, 2.34 and 2.00 times as high as those in wild type wheat, respectively. Excretion H + and cation exchange capacity (CEC) of roots, which were enhanced in transgenic wheat, were positively correlated with K content.The exudate of organic acid intransgenic wheat was 2.22 times as high as that in wild type wheat, leading to the strong K activation of transgenic wheat. Therefore, we assume that well-developed rootsystem containing prosperous root morphology, high excretion H + and CEC of roots and strong excretion ability of organic acids improved K acquisition and utilization efficiency in EdVP1 transgenic wheat.

Moving On Up: H+-PPase Mediated Crop Improvement

“…When grown in K + -limiting soils (Udic-Argosol), these wheat lines show 40% and 50% increases in yield and K + economic utilization index (the relation of shoot K + content and yield), respectively. Furthermore, these plants also develop roots that are at least two times larger and have increased organic acid exudation and rhizosphere acidification capacities compared with controls [10]. All these phenotypes in various crops ( Figure 1C-E) are consistent with an increase in sucrose fluxes from source to sinks as hypothesized by the PP i synthase model ( [3,4,8] and references therein).…”

“…Constitutive expression of root high affinity K + transporters would be instrumental in selectively discriminating K + over Na + under saline conditions, reducing net Na + influx. Enhanced K + uptake capacity is evident when the H + -PPase is enhanced in Arabidopsis plants [12] and in transgenic wheat [10]. When grown in K + -limiting soils (Udic-Argosol), these wheat lines show 40% and 50% increases in yield and K + economic utilization index (the relation of shoot K + content and yield), respectively.…”

H+‐pyrophosphatase IbVP1 promotes efficient iron use in sweet potato [Ipomoea batatas (L.) Lam.]

“…Rhizosphere acidification is a principal mechanism in plant mineral nutrition, because it contributes to nutrient solubility and proton-motive force in the plasma membrane (Palmgren, 2001). Acidification also accelerates auxin transport to increase lateral root branching via up-regulated H + -ATPase and FCR activity (Cho and Hong, 1995;Fr ıas et al, 1996;Li et al, 2000;Zheng et al, 2003), and secretion of organic acids (Ruan et al, 2013;Yang et al, 2007), suggesting increased resilience to Fe deficiency. Nevertheless, the role of H + -PPase in enhancing Fe absorption in plants is largely unknown.…”

Root Foraging Strategy Improves the Adaptability of Tea Plants (Camellia sinensis L.) to Soil Potassium Heterogeneity

“…In the soil K activation experiment, 1.0 g freeze-dried root exudates and 5.0 mL distilled water were added into a 2.5 g air-dried soil sample. In addition, the freeze-dried soil solutions collected from root boxes without tea plants were also used in the soil K activation experiment as the blank [ 53 ]. At the same time, blank control (CK, using distilled water) was also performed.…”