جستجوی مقالات مرتبط با کلیدواژه "biochemical traits" در نشریات گروه "بیوتکنولوژی و ژنتیک گیاهی"

Environmental stress is one of the main factors that reduce the growth and performance of crops and threatening human food security. This study was conducted in order to investigate the effect of drought stress on the changes in biochemical traits and the level of expression of a MYB transcription factor gene in two wheat cultivars (Tajan and Zagros), under drought stress. The experiment was conducted as a factorial based on a completely randomized design with 3 replications. Drought treatments were applied at three levels of 40, 70 and 100% of field capacity 4 weeks after germination. Twenty days after the application of stress, leaves and roots were sampled in order to investigate the expression of MYB genes and measuring some biochemical traits. The results of examining the chlorophyll content under stress showed that the content of chlorophyll a and b decreased with increasing of stress intensity in different genotypes. The rate of reduction of chlorophyll a and b in Tajan genotype under severe stress was higher than Zagros genotype. Also, TBARM content under severe drought stress was significantly higher than moderate stress condition and this increase was seen in Tajen genotype more than Zagros genotype. qRT-PCR analysis showed that the MYB genes showed an increase in expression under drought stress. Furthermore, Zagros genotype, which is considered as a tolerant cultivar to drought stress, had a higher MYB expression level than Tajan cultivar for both genes, suggesting this cultivar for future breeding programs, also considering the importance MYB family genes during drought stress, the results can be used in molecular breeding and pyramiding breeding projects.

Considering the importance of potato in the economy and human nutrition, the need to produce healthy seeds through tissue culture in order to increase the quality of the tuber and ultimately maintain the yield of the product is noticeable. In this regard, the aim of the present study is to evaluate the morphological and biochemical traits in the seedlings of four early and late potato cultivars under in vitro conditions. Four commercial varieties of potato were cultivated as single-node microspecimens in MS culture medium without any plant growth regulators. Seedlings grew after 5 weeks. Seedlings were evaluated in terms of morphological traits (number of seedlings produced from one seedling, stem length, number of branches, nodes, roots and micro-gland) as well as biochemical traits (chlorophyll a, b, carotenoid, anthocyanin, catalase enzyme activity and polyphenol oxidase enzyme activity). In morphological traits, late cultivar Satina, number of seedlings and stem length, and early cultivar Sante showed more roots than other cultivars. In the study of biochemical traits, the late cultivar Agria was superior to other cultivars in terms of the amount of pigments and catalase enzyme. In the same vegetative conditions, different cultivars have different potential in vegetative and biochemical traits. The growth pattern of different genotypes is determined by the synthesis of food and different levels of internal hormones and the balance between them, and as a result, they give different responses to the conditions of the culture environment. The present study showed that in the same vegetative conditions, the early cultivars of Satina in terms of vegetative traits and Agria in terms of the amount of pigments can be selected for mass cultivation.

Soil salinity is one of the most agricultural problems that reduces the growth and yield of crops. Although, barley is the most salinity- tolerant plant among cereals but its seedling stage is the most sensitive developmental stage to salinity stress. Thereby to study the effect of salinity stress at seedling stage on biochemical traits including thiobarbituric acid reactive material (TBARM), catalase activity, and proline values, a factorial based on randomized complete design with four replications was conducted. The experimental factors included two levels of salinity (EC= 0 and 22 ds/m-1) and two barley genotypes (sensitive (Fajr) and tolerant (Afzal)). ANOVA results showed a significate effect for interaction between salinity and genotype (p<0.01) on all traits. Under salinity stress, thiobarbituric acid reactive material (TBARM), catalase activity, and proline values were increased in root and shoot of both genotypes at seedling stage. The higher value of proline and catalase activity, lower level of TBARM were observed in tolerant genotype (Afzal). Therefore, it seems that tolerant genotype copes with the oxidative and osmotic stresses induced by salinity through the increment of antioxidant activity and compatible solutes, respectively. Moreover, relative expression of three genes (NHX3, CAT1 and TIP2;3) in root and shoot were investigated under salinity stress at seedling stage. Expression pattern of NHX3, CAT1 and TIP2;3 genes in tolerant genotype under salinity stress revealed that they play roles in the salinity tolerance of barley. Thereby, aforementioned genes could be used as promising candidate genes for genetic tolerance to salinity stress in crops.