Root plasticity and Pi recycling within plants contribute to low-P tolerance in Tibetan wild barley

Abstract

Background Barley is a low phosphorus (P) demand cereal crop. Tibetan wild barley, as a progenitor of cultivated barley, has revealed outstanding ability of tolerance to low-P stress. However, the underlying mechanisms of low-P adaption and the relevant genetic controlling are still unclear. Results We identified low-P tolerant barley lines in a doubled-haploid (DH) population derived from an elite Tibetan wild barley accession and a high-yield cultivar. The tolerant lines revealed greater root plasticity in the terms of lateral root length, compared to low-P sensitive lines, in response to low-P stress. By integrating the QTLs associated with root length and root transcriptomic profiling, candidate genes encoding isoflavone reductase, nitrate reductase, nitrate transporter and transcriptional factor MYB were identified. The differentially expressed genes (DEGs) involved the growth of lateral root, Pi transport within cells as well as from roots to shoots contributed to the differences between low-P tolerant line L138 and low-P sensitive lines L73 in their ability of P acquisition and utilization. Conclusions The plasticity of root system is an important trait for barley to tolerate low-P stress. The low-P tolerance in the elite DH line derived from a cross of Tibetan wild barley and cultivated barley is characterized by enhanced growth of lateral root and Pi recycling within plants under low-P stress. Electronic supplementary material The online version of this article (10.1186/s12870-019-1949-x) contains supplementary material, which is available to authorized users.

Effects of phosphorus deficiency on the absorption of mineral nutrients, photosynthetic system performance and antioxidant metabolism in Citrus grandis

“…Low P has been shown to inhibit plant growth and decrease agricultural production in areas with low phosphorus fertilizer input. P deficiency led to a significant reduction in net photosynthesis rate and efficiency of the PSII reaction center in rice, sunflower, maize [ 7 – 9 ], sugar beet [ 10 ], soybean [ 11 ], tobacco [ 12 ], oat [ 5 ], sheepgrass [ 14 ], Tibetan wild barley [ 15 ] and tea [ 16 ], thereby significantly decreasing the DW of many crops [ 6 ]. As a result, the grain yield or production of crops is compromised by P deficiency [ 9 ].…”

“…P deficiency caused a significant reduction in net photosynthesis rate and energy capture efficiency of the photosystem II (PSII) reaction center in rice, sunflower and maize [ 7 – 9 ]. The P-deficiency-induced reduction of photosynthesis rate was also reported in sugar beet [ 10 ], soybean [ 11 ], tobacco [ 12 ], Zizania latifolia [ 13 ], oat [ 5 ], sheepgrass [ 14 ], barley [ 15 ] and tea [ 16 ]. As result, the grain yield or production of crops was compromised by P deficiency [ 9 , 17 , 18 ].…”

Greater Morphological and Primary Metabolic Adaptations in Roots Contribute to Phosphate-Deficiency Tolerance in the Bread Wheat Cultivar Kenong199

“…A study based on 215 wheat genotypes demonstrated that genotypes with a greater ratio of seminal lateral root length to seminal axis root length under reduced P condition had a higher root P concentration [42]. Compared to low-P sensitive lines, the tolerant barley lines revealed greater root plasticity in the terms of lateral root length under low-P stress [43]. The adaptation manner in wheat was different from some other plants.…”

Cross Tolerance to Drought and low Phosphorus Stress in Mungbean is Regulated by Improved Antioxidant Capacity, Biological N2-Fixation, and Differential Transcript Accumulation

“…IFRs encode for enzymes involved in the biosynthesis of iso avanoid phytoalexin, which protects plants from abiotic and biotic stresses through its antioxidative properties (Kim et al 2009;Rípodas et al 2013). Upregulation of IFR under low P stress has been observed in soybean (Vengavasi et al 2017), barley (Long et al 2019), and Arabidopsis (Wu et al 2003).…”

“…In irrigated vs. non-irrigated soybean, total iso avone content increased 2.5-fold (Bennett et al 2004), indicating higher iso avone reductase enzymes. IFR has been identi ed as a candidate gene for increased root length in response to low P stress in barley (Long et al 2019). In kidney bean, lateral root elongation and nodule number were related to increased IFR expression (Rípodas et al 2013).…”