The effects of diversified phosphorus nutrition on the growth of oat (Avena sativa L.) and acid phosphatase activity

Abstract

We studied the effect of differential phosphorus (P) supply on the development of oat seedlings (Avena sativa L. ' Arab') as well as localization and activity of acid phosphatases in tissues and root exudates. Plants were grown for 1-3 weeks on nutrient media with inorganic phosphate (+P, control), reduced Pi (0.1 P), phytic acid (PA) as organic P source, and without P addition (−P), in standard conditions or in a split-root culture system. Phosphate starvation reduced shoot growth but increased root elongation and root/shoot ratio, whereas 0.1 P and PA oat plants had similar growth parameters to +P plants. The growth on −P medium significantly decreased Pi content in all tissues, but only a slight Pi decrease was observed in plants grown on 0.1 P and PA media or various split-root system conditions. Pi starvation led to an increase in acid phosphatase (APase) activity in root exudates when compared to +P, 0.1 P, and PA plant samples. APase activity was especially intensive in root cross sections in rhizodermis and around/in vascular tissues of −P plants. For plants grown on 0.1 P medium and on phytic acid, APase activity did not change when compared to the control. Three major isoforms of APases were detected in plant tissues (similar in all studied conditions, with a higher activity of one isoform under Pi deficit). Generally, lowered Pi content (0.1 P) was not stressful to oat plants for up to 3 weeks of culture. Oat plants grew equally well on nutrient media with Pi and on media with phytate, although phytate was considered not available for other plants. The oat plants activated mainly extracellular APases, but also intracellular enzymes, rather via nonlocal signals, to acquire Pi from external/ internal sources under Pi deficiency.

Potato root and leaf phosphatase activity in response to P deprivation

“…(2004). The acid phosphatase activity increased in Arabidopsis shoots in reaction to P deprivation (Wang et al., 2014), but such an increase was inconsistent in oat and soybean depending on the duration of the experiment (Żebrowska et al., 2018; Zhu et al., 2020). However, our second experiment revealed that in older leaves, the acid phosphatase activity was increased in response to P deprivation.…”

Faba bean (Vicia faba L.) varieties reveal substantial and contrasting organic phosphorus use efficiencies (PoUE) under symbiotic conditions

“…Plants have developed a wide array of morphological, physiological, and biochemical strategies to promote Po mobilization (Sulieman & Mühling, 2021, and references therein). At present, two principal mechanisms are chronicled to improve P use efficiency (PUE) by plants: P acquisition efficiency (PAE) or the capacity of the plant to acquire P from the external environment, and P utilization efficiency (PUtE), which describes the plant's ability to conserve P use internally (Deng et al., 2018; Irfan et al., 2020; Zebrowska et al., 2018). The plant traits related to these strategies could be exploited to create P‐efficient genotypes that can grow effectively under low Pi conditions (van de Wiel et al., 2016; Yaseen & Malhi, 2009).…”