The enhancement of drought tolerance for pigeon pea inoculated by arbuscular mycorrhizae fungi

Abstract

Pigeon pea (Cajanus cajan) has been rapidly grown in the drought-striken Karst regions of southwest China. Present research aimed to investigate the effects of arbuscular mycorrhizae (AM) on the drought tolerance of pigeon pea, as well as to elucidate the physiological responses of AM-colonized seedlings to the water deficit. As subjected to drought stress, AM symbiosis (AMD) highly led to the positive effects on root system, plant height and stem diameter. AMD demonstrated a remarkably higher chlorophyll content, photosynthetic rate and stomatal conductance. The soluble sugar in AMD was significantly higher than that of the non-AM seedlings (NAMD), indicating the enhanced tolerance at least partially correlated with osmotic solute. Conversely, the proline (Pro) of AMD was lower, revealing the excessive Pro was not imperative for drought tolerance. After 30 days drought stress, AMD gave around a third less lipid peroxides than that of NAMD. Rather, the root activities of AMD were significantly higher than that of the latter after 10 days drought stress. Thereby, AM fungi might substantially elevate the tolerance to drought of pigeon pea, and the cumulative effects contributed to the enhanced tolerance. To date, this has been the first report concerning the enhancement of drought tolerance via AM colonization in this legume species.

Arbuscular mycorrhiza improved growth performance in Macadamia tetraphylla L. grown under water deficit stress involves soluble sugar and proline accumulation

“…In AM pretreated plants, there was an increase in soluble sugar content in leaf tissues of the both ''H2'' and ''660'' cultivars. These observations are in parallel to earlier observation made in leaf tissues of AM treated C. tangerine (Wu and Xia 2006;Wu et al 2007), AM treated pigeon pea (Qiao et al 2011) and AM treated lettuce cultivars (Baslam and Goicoechea 2011). Soluble sugar in water stressed leaves of AM-associated C. tangerine plants was enhanced by 1.37-folds of that in well-watered control plants (Wu and Xia 2006).…”

“…Plant morphology and growth performance in AM-pretreated water stressed plants were better than those without AM pretreatment. Water relation in the leaf tissues and water oxidation in the photosystem II of light reaction are the key factors in maintaining the photosynthetic abilities (chlorophyll pigments, chlorophyll fluorescence and net photosynthetic rate) under water deficit conditions (Wu et al 2007;Qiao et al 2011). Low value of F v / F m indicates a reduction of photosynthesis and reflects a decline in growth (Oliveira and Penũelas 2004).…”

Arbuscular mycorrhizal inoculation and super phosphate application influence plant growth and yield of Capsicum annuum

“…the chlorophyll content, phosyntesis and stomatal conductance as compared to the uninoculated control. Increased chlorophyll content on inoculation with AM fungi is also reported by Qiao et al (2011). The highest increase in photosynthetic rate, that was measured as chlorophyll a (123.06±2.4), chlorophyll b (448.5±4.75), photosynthesis (51.06±2.96) and stomatal conductance both on the upper (0.272±0.0084) and lower (0.834±0.009) side was markedly enhanced in G+A+Pf of F1.…”

Molecular cloning of an S-adenosylmethionine synthase gene from pigeon pea (Cajanus cajan) and its expression analysis under arbuscular mycorrhizae fungi colonization and drought stress

“…As a tropical grain-legume, it has demonstrated high tolerance to drought stress (Otieno et al, 2011). Recently, it had been rapidly extended in the drought-stricken karstic regions of southwestern China (Qiao et al, 2011). Arbuscular mycorrhizae fungi (AMF) was characterized by highly branched haustorium-like fungal structures within root cortical cells, and the fungi could release signal molecules and form 'Myc factors' that triggered symbiotic root responses (Parniske et al, 2008), leading to an elevation in plant tolerance to drought stress.…”

“…In plants, SAMS is regarded as a vital enzyme candidate that is required during drought stress (Gill and Tuteja 2010). Previously, AMcolonized pigeon pea substantially demonstrated the elevated tolerance to drought stress via regulating the comprehensive effects (Qiao et al, 2011). To unravel the molecular mechanism of drought resistance in pigeon pea, we constructed a drought stress suppressive subtraction hybridization (SSH) cDNA library, and obtained an EST of SAMS cDNA , which was preliminarily justified to be a drought-responsive gene of this species (Qiao et al, 2012).…”