Germination response of endophytic Festuca rubra seeds in the presence of arsenic

Abstract

Epichloë fungal endophytes colonize the intercellular space of aerial organs of their plant hosts without causing symptoms. These symbionts are known to improve the performance of their host grasses in some situations of biotic and abiotic stress, leading to the suggestion that they can be used to improve grass tolerance to contaminants. The grass Festuca rubra is a host of the endophyte Epichloë festucae. We used two half‐sib lines of F. rubra, each line composed of infected (E+) or endophyte‐free (E−) seeds, to study the effect of varying levels of arsenic (6, 12, 25, and 50 mg L−1), and of the endophyte in seed germination and radicle growth. The results showed that seed germination was not significantly affected by arsenic (As) levels lower than 25 mg L−1, indicating that this grass has a relatively high tolerance of As at the germination stage. The decrease in germination observed at 25 and 50 mg L−1 was due to increased seed mortality and to the reversible inhibition of the germination of viable seeds caused by As. The presence of the endophyte did not change the germination response to arsenic of one line, but affected negatively the germination of the other line. In contrast to the process of germination, radicles of E+ seeds of both lines were longer than those of endophyte‐free seeds. The results of this work indicate that Epichloë endophytes can affect the performance of some F. rubra genotypes when As is present in the soil.

Fungal Endophyte (Epichloë festucae) Alters the Nutrient Content of Festuca rubra Regardless of Water Availability

“…It is important to point out that the observed increase in nutrient concentration due to the endophyte was not dependent on the F. rubra host plant line. Endophyte effects on plant performance are either elusive or reported to be determined by host plant genotype [ 17 , 20 – 23 , 25 , 28 , 33 , 35 ]. Our results were based on only two F. rubra plant lines, but it is remarkable that in spite of the large differences between lines in shoot and root biomass, the effect of fungal endophyte was similar for the nutrients P, N and Zn, as shown by the sample ordination ( Figure 6 ).…”

“…Nevertheless, subsequent studies have shown that the endophyte effect on host plants is dependent on the plant and fungal genotypes and the environmental conditions. For example, the host plant and fungal genotype determine the endophyte effect on plant growth [ 17 - 21 ], plant nutrient content [ 22 , 23 ] or seed survival [ 24 , 25 ]. Thus, at the present time plant-endophyte interactions are considered to be variable and to range from antagonistic to mutualistic [ 3 , 12 , 26 , 27 ].…”

Accumulation of Arsenic by Plants Growing in the Sites Strongly Contaminated by Historical Mining in the Sudetes Region of Poland

“…It has been proved that several plant species growing in strongly contaminated sites can develop various tolerance mechanisms that lead to reduced uptake of As, either by adaptation of the arsenate uptake system or by avoidance and exclusion [20][21][22][23][24][25]. Mycorrhiza, as well as rhizospheric and endophytic bacteria can additionally reduce the influx of As to plant roots therefore supporting the tolerance to its high concentrations in soils [26][27][28]. On the other hand, however, some plants species, particularly those growing in aquatic conditions or wetlands, can intensively take up As and tolerate its high concentrations in shoots.…”

Effect of arsenate on germination and early development parameters of three forage leguminous plants

“…The reduction on the percentage of germination was documented for several plant species (TALUKDAR 2011, UPADHYAYA et al 2014. VAZQUEZ ALDANA et al (2013) reported an adverse effect on the germination of Festuca rubra seeds exposed to As that was significant only when its concentration was >12 mg/L, a value more elevated than the As levels used in this experience. Nevertheless, our results suggest that seeds can germinate in a wide range of As concentrations present in irrigation water.…”