Influence of arbuscular mycorrhizal fungi and kinetin on the response of mungbean plants to irrigation with seawater

Abstract

Increasing use of saline water in irrigation can markedly change the physical and chemical properties of soil. An experiment was carried out to investigate the interaction between the mycorrhizal fungus Glomus clarum, isolated from a saline soil, and kinetin on the growth and physiology of mungbean plants irrigated with different dilutions of seawater (0, 10, 20, and 30%). The growth, chlorophyll concentration and sugar content of mycorrhizal plants was greater than that of non-mycorrhizal plants under all conditions (with or without seawater). The dry weight of both mycorrhizal and non-mycorrhizal mungbean plants irrigated with 10% seawater was significantly increased by treatment with kinetin. The mycorrhizal symbiosis increased root:shoot dry weight ratio, concentrations of N, P, K, Ca and Mg, plant height, protein content, nitrogen or phosphorus-use efficiencies, and root nitrogenase, acid or alkaline phosphatase activities of seawater-irrigated mungbean plants, with little or no effect of kinetin. Kinetin treatment generally decreased chlorophyll concentration and sugar content in mycorrhizal plants as well as Na/N, Na/P Na/K, Na/Ca and Na/Mg ratios. Root colonization by G. clarum was increased by irrigation with seawater, and kinetin had no consistent effect on fungal development in roots. This study provides evidence that arbuscular mycorrhiza can be much more effective than kinetin applications in protecting mungbean plants against the detrimental effects of salt water.

Influence of arbuscular mycorrhiza on osmotic adjustment compounds and antioxidant enzyme activity in nodules of salt-stressed soybean (Glycine max) / VPLIV ARBUSKULARNE MIKORIZE NA SPOJINE OSMOTSKE PRILAGODITVE IN ANTIOKSIDACIJSKO ENCIMSKO AKTIVNOST V NODULIH SOJE (Glycine max (L.) Merr.) V SLANOSTNEM STRESU

“…Higher K + accumulation by inoculated plants in saline soil could be beneficial by maintaining a high K + /Na + ratio and by influencing the ionic balance of the cytoplasm or Na + efflux from plants (Giri et al, 2007;Aleman et al, 2009). Improved ionic ratios in the aerial parts of inoculated-stressed plants have been reported earlier by Giri et al (2003); Rabie (2005); Rabie and Almadini (2005).…”

Mycorrhizal colonization of transgenic Eucalyptus camaldulensis carrying the mangrin gene for salt tolerance

“…This finding might also be due to the positive effects of AM fungi on plant growth and nutrient acquisition as reported in other AM fungi-inoculated plants grown under saline stress (Giri and Mukerjii 2004;Rabie 2005). In another study, higher chlorophyll contents were reported in mycorrhizal zucchini plants grown under Effects of plant genotype (G: nontransgenic or mangrin transgenic), treatment (T: tap water or 200 mM NaCl), and both interactions.…”

Tolerância e potencial fitorremediador de Stizolobium aterrimum associada ao fungo micorrízico arbuscular Glomus etunicatum em solo contaminado por chumbo

“…A atividade nitrogenase de nódulos de plantas crescendo nas doses de 500 e 1.000 mg dm -3 Pb foi maior em plantas micorrizadas que em não micorrizadas (Figura 6). Semelhantemente ao observado por Balestrasse et al (2003) em plantas de soja sob estresse por Cd, aquelas não micorrizadas apresentaram pequena redução na atividade da nitrogenase, evidenciando que diferentes MPs podem causar efeito negativo sobre a fixação biológica de N. Como demonstrado por Rabie (2005b) em plantas de Vigna radiata sob condições de estresse salino e por Frason et al (1991) em plantas de soja sob estresse hídrico, a micorrização estimulou a atividade da nitrogenase nessas plantas. Frason et al (1991) sugerem que plantas micorrizadas sob condições de estresse abiótico podem apresentar melhor desempenho na fixação de N 2 em função, possivelmente, do maior suprimento de P fornecido aos nódulos pela associação com FMAs, uma vez que o processo de fixação de N 2 tem alta demanda de energia.…”