Role of fungal endophyte of tall fescue ( Epichloë coenophiala ) on water availability, wilting point and integral energy in texturally-different soils

2018 ◽

Vol 115 (22) ◽

pp. 5692-5697 ◽

Cited By ~ 13

Author(s):

Cathy Hohenegger ◽

Bjorn Stevens

Keyword(s):

Soil Moisture ◽

Water Availability ◽

Precipitation Field ◽

Resistance Function ◽

Permanent Wilting Point ◽

Low Levels ◽

Dry Out ◽

Self Aggregation ◽

Wilting Point

Convection-permitting simulations on an idealized land planet are performed to understand whether soil moisture acts to support or impede the organization of convection. Initially, shallow circulations driven by differential radiative cooling induce a self-aggregation of the convection into a single band, as has become familiar from simulations over idealized sea surfaces. With time, however, the drying of the nonprecipitating region induces a reversal of the shallow circulation, drawing the flow at low levels from the precipitating to the nonprecipitating region. This causes the precipitating convection to move over the dry soils and reverses the polarity of the circulation. The precipitation replenishes these soils with moisture at the expense of the formerly wet soils which dry, until the process repeats itself. On longer timescales, this acts to homogenize the precipitation field. By analyzing the strength of the shallow circulations, the surface budget with its effects on the boundary layer properties, and the shape of the soil moisture resistance function, we demonstrate that the soil has to dry out significantly, for the here-tested resistance formulations below 15% of its water availability, to be able to alter the precipitation distribution. We expect such a process to broaden the distribution of precipitation over tropical land. This expectation is supported by observations which show that in drier years the monsoon rains move farther inland over Africa.

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Indirect interactions among co-infecting parasites and a microbial mutualist impact disease progression

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2021.1313 ◽

2021 ◽

Vol 288 (1956) ◽

pp. 20211313

Author(s):

Kayleigh R. O'Keeffe ◽

Anita Simha ◽

Charles E. Mitchell

Keyword(s):

Disease Progression ◽

Tall Fescue ◽

Fungal Endophyte ◽

Indirect Interactions ◽

Symptom Development ◽

Facilitative Effect ◽

Interaction Modification ◽

Colletotrichum Cereale ◽

Microbial Symbionts ◽

Epichloë Coenophiala

Interactions among parasites and other microbes within hosts can impact disease progression, yet study of such interactions has been mostly limited to pairwise combinations of microbes. Given the diversity of microbes within hosts, indirect interactions among more than two microbial species may also impact disease. To test this hypothesis, we performed inoculation experiments that investigated interactions among two fungal parasites, Rhizoctonia solani and Colletotrichum cereale, and a systemic fungal endophyte, Epichloë coenophiala, within the grass, tall fescue ( Lolium arundinaceum ). Both direct and indirect interactions impacted disease progression. While the endophyte did not directly influence R. solani disease progression or C. cereale symptom development, the endophyte modified the interaction between the two parasites . The magnitude of the facilitative effect of C. cereale on the growth of R. solani tended to be greater when the endophyte was present. Moreover, this interaction modification strongly affected leaf mortality. For plants lacking the endophyte, parasite co-inoculation did not increase leaf mortality compared to single-parasite inoculations. By contrast, for endophyte-infected plants, parasite co-inoculation increased leaf mortality compared to inoculation with R. solani or C. cereale alone by 1.9 or 4.9 times, respectively. Together, these results show that disease progression can be strongly impacted by indirect interactions among microbial symbionts.

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Deletion of the Fungal Gene soft Disrupts Mutualistic Symbiosis between the Grass Endophyte Epichloë festucae and the Host Plant

Eukaryotic Cell ◽

10.1128/ec.00191-12 ◽

2012 ◽

Vol 11 (12) ◽

pp. 1463-1471 ◽

Cited By ~ 36

Author(s):

Nikki D. Charlton ◽

Jun-Ya Shoji ◽

Sita R. Ghimire ◽

Jin Nakashima ◽

Kelly D. Craven

Keyword(s):

Host Plant ◽

Tall Fescue ◽

Fungal Endophyte ◽

Plant Host ◽

Content Type ◽

Mutualistic Symbiosis ◽

Epichloë Festucae ◽

Mutant Strains ◽

Hyphal Anastomosis

ABSTRACT Hyphal anastomosis, or vegetative hyphal fusion, establishes the interconnection of individual hyphal strands into an integrated network of a fungal mycelium. In contrast to recent advances in the understanding of the molecular basis for hyphal anastomosis, knowledge of the physiological role of hyphal anastomosis in the natural habitats of filamentous fungi is still very limited. To investigate the role of hyphal anastomosis in fungal endophyte-plant interactions, we generated mutant strains lacking the Epichloë festucae soft ( so ) gene, an ortholog of the hyphal anastomosis gene so in the endophytic fungus E. festucae . The E. festucae Δ so mutant strains grew similarly to the wild-type strain in culture but with reduced aerial hyphae and completely lacked hyphal anastomosis. The most striking phenotype of the E. festucae Δ so mutant strain was that it failed to establish a mutualistic symbiosis with the tall fescue plant host ( Lolium arundinaceum ); instead, it killed the host plant within 2 months after the initial infection. Microscopic examination revealed that the death of the tall fescue plant host was associated with the distortion and disorganization of plant cells. This study suggests that hyphal anastomosis may have an important role in the establishment/maintenance of fungal endophyte-host plant mutualistic symbiosis.

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The role of endophyte in determining the persistence and productivity of ryegrass, tall fescue and meadow fescue in Northland

Proceedings of the New Zealand Grassland Association ◽

10.33584/jnzg.2009.71.2754 ◽

2009 ◽

pp. 145-150 ◽

Cited By ~ 10

Author(s):

D.E. Hume ◽

B.M. Cooper ◽

K.A. Panckhurst

Keyword(s):

Tall Fescue ◽

Festuca Arundinacea ◽

Fungal Endophyte ◽

Festuca Pratensis ◽

Meadow Fescue ◽

Endophyte Infection ◽

African Black ◽

Small Plot ◽

Insect Attack

Evidence from small plot and farm trials demonstrate that fungal endophyte infection plays a pivotal role in enhancing the persistence and yields of perennial, hybrid and Italian ryegrasses, tall and meadow fescues in Northland. In most situations these effects were evident within 2-3 years of sowing and were largely attributed to protection from insect attack that is conferred by endophyte infection. Keywords: fungal endophyte, Neotyphodium, perennial ryegrass, Lolium perenne, tall fescue, Festuca arundinacea, meadow fescue, Festuca pratensis, African black beetle, Heteronychus arator

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THE ROLE OF GRASSLAND IN MANAGEMENT

Proceedings of the New Zealand Grassland Association ◽

10.33584/jnzg.1968.30.1259 ◽

1968 ◽

pp. 44-49

Author(s):

B.K. Cameron

Keyword(s):

Soil Temperature ◽

Annual Rainfall ◽

Silt Loam ◽

Average Annual Rainfall ◽

Very High ◽

Wilting Point

THE PROPERTY to be discussed is a mixed sheep and cropping unit, situated ei ht a miles east of Ashburton and midway between the Ra aia and the Ashburton rivers. Average annual rainfall is 27 in., evenly spread, but there is very high summer evaporation and therefore frequent droughts. On average, the soil is below wilting point for 40 to 50 days each summer. Winters are cold with the soil temperature being below 48°F for about four months each year. The soil is a Lismore stony silt loam averaging 9 in. in depth over gravel.

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