RESUMEN
Grass pea (Lathyrus sativus) is a legume with various adverse adaptability and rich nutrition. However, it can lead to the human and animal neurotoxicity after long-term consumption due to its neurotoxin, beta-N-oxalyl-L-alpha, beta-diaminopropionic acid (beta-ODAP), limiting its utilization. This paper summarized the influences of beta-ODAP on osmotic adjustment and growth regulation in grass pea under drought stress, the research progress in analysis methods, toxicological mechanisms and practical utility of beta-ODAP, and the breeding strategies for low- and zero-beta-ODAP. Beta-ODAP synthesis was found to be abundant in grass pea under drought stress and its content was enhanced gradually with the increasing extent of drought stress. beta-ODAP could supply nitrogen for plant growth and seed development, scavenge reactive oxygen species (ROS), involve in osmotic adjustment as a soluble amino acid, transport zinc-ions as a carrier molecule, and impact nodule development. However, increasing the content of sulfur-containing amino acids (methionine and cysteine) could decrease the level of toxicity of grass pea. There were a lot of investigations on collecting genetic resources, cross breeding, tissue culture, and gene manipulation for low- and zero-toxin in grass pea in recent years. Although beta-ODAP could induce excitotoxicity by damaging intracellular Ca2+ homeostasis and as glutamate analogues, it has medicinal value on hemostasis and anti-tumor.
Asunto(s)
Aminoácidos Diaminos/química , Lathyrus/química , Neurotoxinas/química , Aminoácidos , Sequías , Especies Reactivas de OxígenoRESUMEN
Interrelationship among abscisic acid (ABA) content, accumulation of free polyamines and biosynthesis of beta-N-oxalyl-l-alpha,beta-diaminopropionic acid (ODAP) was studied in grass pea (Lathyrus sativus L.) seedlings under drought stress induced by 10% polyethylene glycol (PEG6000). Increase of ABA content occurred prior to that of ODAP and polyamine contents, and was found significantly positive correlation between ABA content and ODAP content. Addition of exogenous ABA increased ODAP content in leaves. On the other hand, pretreatment with alpha-difluoromethylarginine (DFMA), a polyamine biosynthesis inhibitor, significantly suppressed the accumulation of free putrescine (Put), free spermidine (Spd) and free spermine (Spm), which in turn inhibited biosynthesis of ODAP in well-watered leaves. Meanwhile, addition of exogenous Put alleviated DFMA-induced inhibition on the biosynthesis of Put and Spd, but did not affect the biosynthesis of Spm and ODAP in well-watered leaves. Same result was also achieved in drought-stressed leaves. Increasing accumulation of ODAP was significantly correlated with increasing Spm content (R=0.7957**) but not with that of Spd and Put. Therefore, it can be argued that ABA stimulated the biosynthesis of ODAP simultaneously with increasing the level of free Spm under drought stress condition.
Asunto(s)
Ácido Abscísico/farmacología , Aminoácidos Diaminos/metabolismo , Lathyrus/efectos de los fármacos , Lathyrus/metabolismo , Espermina/metabolismo , Reguladores del Crecimiento de las Plantas/farmacología , Polietilenglicoles/farmacología , Plantones , Factores de Tiempo , Agua/metabolismoRESUMEN
Lathyrus sativus (grass pea) is a high-yielding, drought-resistant legume consumed as a food in Northern India and neighboring countries as well as in Ethiopia. Its development into an important food legume, however, has been hindered by the presence of the neurotoxin - beta-N-oxalyl-L-alpha,beta-diaminopropionic acid (beta-ODAP) in seeds which, if consumed in large quantities for prolonged periods, can cause irreversible paralysis. Recently, some low-toxin lines have been developed that may prove safe for both animal and human foods. Cultivation of L. sativus should thus be considered in suitable regions because the demand for legume animal feed protein products is expected to increase. This paper addresses advances in understanding L. sativus from the perspective of its taxonomy, genetics, ecology, chemistry, nutrition, medicine, biology and for animal nutrition.
Asunto(s)
Aminoácidos Diaminos , Lathyrus , Neurotoxinas , Aminoácidos Diaminos/química , Aminoácidos Diaminos/metabolismo , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Humanos , Lathyrus/química , Lathyrus/genética , Lathyrus/metabolismo , Neurotoxinas/química , Neurotoxinas/metabolismo , Valor Nutritivo , Semillas/químicaRESUMEN
In this study, Embryogenic and non-embryogenic calli were separately obtained by cultivation of leaf segments on MS medium containing and not containing 2,4-D 0.2 mg/L. The calli were transferred to an 2,4-D-free MS medium containing different concentrations of (45)Ca(2+) and EGTA cultured, and microscopic examination of tissue sliced, gamma-ray energy spectrum analysis, ELISA and two-dimensional polyacrylamide-gel electrophoresis were used to study the relation between changes in Ca(2+) concentration and protein composition changes during somatic embryogenesis. The results showed that: (1) Calli of dedifferentiation were obtained by cultivating in the inductive medium (MS+2,4-D 0.2 mg/L) and then transferred to the 2,4-D-free (MS) differentiation medium. After cultivating, the large number of embryogenic cells divided and somatic embryogenic calli (EC) were formed; embryogenic cell differentiation and somatic embryo ware not formed when the dedifferentiation calli, which were cultivated in the inductive medium without 2,4-D, ware transferred to the cultivating of differentiation, so calli were called non-embryogenic calli (NEC). (2) SE frequency of EC was rised with exogenous Ca(2+) concentration was going up, and adding peak value (70.5% to 74.5%) when Ca(2+)concentration was from 0.8 to 1.6 mmol/L, then SE frequency was dropped markedly with Ca(2+) concentration was farther increasing. Formation of meristematic cell aggregates of NEC was also enhanced when exogenous Ca(2+) concentration was from 0.8 to 1.6 mmol/L. (3) After adding EGTA, which was Ca(2+) antagonist, SE frequency was dropped markedly, and SE frequency was fallen along with increased of EGTA concentration. When EGTA concentration went up to 1.2 micromol/L, SE frequency dropped to 5%, and the formation of meristematic cell aggregates on NEC was inhibited. (4) When 2 microCi (45)Ca(2+)/mL was added, the uptake of (45)Ca(2+) by EC and NEC was different, two uptake peaks of (45)Ca(2+)appeared in EC at the embryogenic cell differentiation of stage, and the uptake of (45)Ca(2+) of EC was 4-5 times higher than that of NEC, and the uptake frequency of (45)Ca(2+) improved from 54.1% to 74.5%. The uptake of (45)Ca(2+) by NEC during development not only was lower than that by EC but also there were no such marked peak as those with EC. (5) The CaM content examined by ELISA was increased markedly at multi-cellular embryo and globular embryoid stage of EC. After adding Ca(2+), the CaM content increased significantly, the CaM content of EC was 2-3 times that of NEC. (6) The IEF/SDS-PAGE results showed that the numbers and amount of protein components were widely different between the two kinds of callus with different morphogenesis patterns, the number of proteins of EC had more components than those of NEC. The largest differences protein species presented with Ca(2+) ware added, the more proteins presented on the range of molecular weight was from 43 kD to 66 kD and pI values was from 4.0 to 7.0.
Asunto(s)
Calcio/farmacología , Lycium/embriología , Calcio/metabolismo , Calmodulina/análisis , Ácido Egtácico/farmacología , Lycium/metabolismo , Proteínas de Plantas/análisisRESUMEN
In order to research the function mechanism of the 2,4-D during the development of plant somatic embryogenesis, we studied its function mechanism and relationship with the space-time distributing of Ca2+ content and ATPase activity on somatic embryogenesis of Lycium barbarum L. The possible effects on 2,4-dichlorophenoxyacetic acid (2,4-D) induced somatic embryogenesis and changes of Ca2+ and ATPase active at different development period of somatic embryogenesis. The result showed: The 2,4-D was a key hormone for induced embryonic state of Lycium barbarum L. The embryonic callus and non-embryonic callus was separately obtained in the medium that contains the auxin 2,4-D and lack 2,4-D. In the present study, we have observed the Ca2+ was more abundant in the further intercellular matrix and on the cell wall at the multi-cellular stage, and Ca2+ was concentrated in the plasma membrane and vacuoles membrane during embryonic cell differentiate and division, to the globular embryo, more Ca2+ was seen in the nucleus. Afterward, it was also observed to be distributed in the thicken cell wall and intercellular matrix. At the same process, the variations of ATPase activity and Ca2+ were highly similar, ATPase activity was mainly located on the plasma membrane in early embryogenic cells. With further development, it was also observed to be distributed in endoplasm, nucleus and vacuoles, with the thickening of embryogenic cell wall, ATPase activity was found in the thickened region and the intercellular space. However, the variations of ATPase activity and Ca2+ have not clearly observed variety dynamics at the nonembryogenic callus, and with further vacuolation of nonembryogenic cell, Ca2+ content and ATPase activity gradually drop. It was indicated there was a closely relationship between the dynamics of Ca2+ and ATPase activity in somatic embryogenesis by 2,4-D induced. And the space-time distribution of Ca2+ and ATPase activity play a key role on signal transmission and the regulation of relevant gene expression.