Melatonin: Role in Increasing Plant Tolerance in Abiotic Stress Conditions

Nowadays, due to the environmental stress factors that limit the production of crops, it has become very difficult to find suitable areas to enable the plant to reach its optimum product potential. Abiotic stress is very effective in decreasing agricultural production. Factors such as drought, salinity, high and low temperature, flood, radiation, heavy metals, oxidative stress, and nutrient deficiency can be considered as abiotic stress factors, and these sources of stress negatively affect plant growth, quality and productivity. Melatonin (MEL) was first identified in plants in 1995 and is increasingly becoming important for its role and effects in the plant system. MEL has been shown to have a substantial role in plant response to growth, reproduction, development, and different stress factors. In addition to its regulatory role, MEL also plays a protective role against different abiotic stresses such as metal toxicity, temperature, drought, and salinity. In plants, an important role of MEL is to alleviate the effects of abiotic stresses. In this review, the effects of MEL on plant growth, photosynthetic activity, metabolism, physiology, and biochemistry under abiotic stress conditions as a plant growth regulator will be examined

The effect of different bacteria biofotmulation applications on plant growth, yield and enzyme levels in garlic cultivation

Bu çalışmada; yabani ve kültür bitkilerinin toprak altı veya toprak üstü aksamlarından daha önce yürütülen bazı çalışmalarda izole edilerek tanılanan, toplam 1248 bakteri izolatı içerisinden seçilen Agrobacterium sp., Bacillus sp., Pantoea sp. ve Pseudomonas sp.’e ait toplam 19 adet bakteri izolatı kullanılarak 3 farklı bakteri biyoformülasyonu (F1, F2 ve F3) hazırlanmıştır. Bu biyoformülasyonlar içerisine daldırılan sarımsak (Allium sativum L.) dişleri saksılara ekilerek uygulamaların bitki boyu, klorofil düzeyi ve bazı enzim (katalaz, peroksidaz, polifenol oksidaz ve superoksit dismutaz) aktiviteleri üzerine etkileri saptanmıştır. Tüm bakteri formülasyonu uygulamalarının kontrole göre sarımsakta bitki gelişiminde önemli katkılar sağladığı ve bitki enzim düzeylerinde de önemli değişikliklere sebep olduğu görülmüştür. Sonuç olarak; test edilen 3 bakteri biyoformülasyonu içerisinde özellikle B2 formülasyonunun hem bitki gelişim parametreleri hem de bitkideki enzim düzeyleri bakımından yapılan değerlendirmede sarımsak tarımında mikrobiyal gübre olarak kullanılabileceği düşünülmektedir.In this study, we have prepared 3 different bacteria bioformulation (F1, F2 and F3) by using a total 19 bacteria isolates belonging to Agrobacterium sp., Bacillus sp., Pantoea sp.and Pseudomonas sp. chosen and identidfied 1248 bacteria isolate from underground or above – ground parts of the wild and cultivated plants in several studies conducted previously. Cloves of garlic (Allium sativum L.) that had been submerged into these bioformulations were potted and had been determined their effects on plant height, chlorophyll level and some enzyme (catalase, peroxidase, polyphenol oxidase and superoxide dismutase) activities. It has been found out that all bacteria formulation treatments made important contributions to the plant growth of garlic compared to the control, and caused important changes in the plant enzyme levels. As a result, it is thought that B2 formulation, among the three bacteria bioformulations tested, could be used a microbial fertilizer in garlic agriculture due to its plant growth parameters and enzyme levels in plant

Roles of Bacillus megaterium in Remediation of Boron, Lead, and Cadmium from Contaminated Soil

Phytoremediation is an attractive, economical alternative to soil removal and burial methods to remediate contaminated soil. The objective of this study was to investigate the effects of adding different rates of Bacillus megaterium on the capacity of Brassica napus plants to take up boron (B), lead (Pb), and cadmium (Cd) from polluted soils under field conditions. Field experiments were conducted using a randomized complete block design with control (without pollution and B. megaterium application) and B, Pb, and Cd in two doses (0 and 100 mg kg(-1)), B. megaterium with four doses (no application and 10(8) cfu B. megaterium ml(-1) sprayed at 50 ml plot(-1), 100 ml plot(-1), 150 ml plot(-1)). Results indicated that soil pollution treatments significantly decreased seed (SDMY), shoot (SHDMY), root (RDMY), and total dry-matter yield (TDMY) of plants at 42.9, 3.8, 62.6, and 23.4% for B-polluted treatment; 25.8, 8.7, 17.6, and 14.2% for Pb-polluted treatment; and 33.2, 7.0, 14.0, and 16.4% for Cd-treatment without B. megaterium application, respectively. However, the application of B. megaterium ameliorated the negative effects of B, Pb, and Cd at 41.4, 52.7, and 10.9% for B; 24.4, 21.6, and 4.9% for Pb; and 22.8, 22.0, and 3.3% for Cd, respectively. The potentially bioavailable and relatively available fraction of soil B, Pb, and Cd increased with increases in the B. megaterium application but total fraction and stable fraction decreased. It is concluded that the seed and shoot parts of B. napus can be used as hyperaccumulators for plant B, Pb, and Cd remediation according to remediation factors but the shoot is the biggest part of the plant, and thus an important portion of the plant to remove B, Pb, and Cd from the B-, Pb-, and Cd-contaminated soils. To decrease desired concentration for 8 mg B kg(-1), 4 mg Pb kg(-1), and 3 mg Cd kg(-1) in the active rooting zone of soil, approximately 2, 6, and 21 years would be necessary with only 150 ml plot(-1)B. megaterium-sprayed soil cultivated with B. napus, respectively

YIELD AND CHEMICAL COMPOSITION OF CORN (ZEA MAYS L.) AS AFFECTED BY BORON MANAGEMENT

ABSTRACT: Boron (B) deficiency is widespread in the Anatolia region of Turkey. This could impact production and quality of corn (Zea mays L.) A 2-yr field experiment was conducted for determine the optimum economic B rate (OEBR), critical soil test and tissue B values for yield and quality response of corn to B fertilizer soil application (SA) at 5 doses (0, 1, 3, 9 and 12 kg B ha -