Research Progress on Effects of Proline on Reproductive Performance of Sows

Proline is a cyclic α-imino acids,meanwhile it also can be considered as a functional amino acid for mammals and plays an important role in protein synthesis,organism metabolism,wound healing,anti-oxidant and immune reactions. The studys have found that extra dietary supplementation of moderated proline has great significance in improving the growth and development of conceptus,piglets, embryo,mammary gland and placenta of sows,at the same time it also can prevent intrauterine growth restriction. The author reviewed structure characters and physicochemical properties,anabolism and catabolism of proline,and especially focused on its effects on the reproductive performance of pregnancy sows and potential regulation mechanism aiming to provide some help for the researchers in the field of sows.     

Salt‐Induced Regulation of Some Key Antioxidant Enzymes and Physio‐Biochemical Phenomena in Five Diverse Cultivars of Turnip (Brassica rapa L.)

A greenhouse experiment was carried out to examine the differential morpho‐physiological responses of five cultivars of turnip (Brassica rapa L.) to salt stress. Five diverse cultivars of turnip (shaljum desi surakh, shaljum purple top, shaljum golden bal, neela shaljum, and peela shaljum) were subjected for 6 weeks to varying levels of NaCl, i.e. 0, 80 and 160 mm in Hoagland’s nutrient solution in sand culture. Imposition of varying levels of salt substantially decreased shoot and root fresh and dry weights, chlorophyll contents, leaf osmotic potential, relative water contents, different gas exchange attributes, total phenolics, malondialdehyde, activities of superoxide dismutase, peroxidase catalase, and leaf and root K⁺ levels while enhanced the proline contents, membrane permeability, level of H₂O₂, leaf and root Na⁺ and Cl^? and leaf Ca²⁺ in all turnip cultivars under study. Of all cultivars, peela shaljum and neela shaljum were consistently higher in their growth than the other turnip cultivars at all salt concentrations of the growth medium. Photosynthetic capacity (A) and stomatal conductance (g_s) were higher in high biomass‐producing cultivars, i.e. peela shaljum and neela shaljum, which provide to be potential selection criteria of salt tolerance in turnip. However, the regulation of antioxidant system was cultivar‐specific under saline conditions.     

水分胁迫下植物乙烯,脯氨酸积累气孔反应的研究现状

对植物在水分胁迫下乙烯，脯氨酸积累，气孔反应的研究现状以及这些指标在水胁迫下的生理特征进行了探讨，以期为植物的抗旱性品种选育，提高作物产量，发展干旱地区农业生产提供参考。     

Chilling Tolerance, Cold Hardening and Freezing Tolerance of Low-temperature-tolerant Mutants of Dendranthema × grandiflorum (Ramat.) Kitamura

Two low-temperature-tolerant mutants of the Dendranthema × grandiflorum (Ramat.) Kitamura cultivar ‘Puck’ derived from an x-radiated tissue culture system were compared, as vegetatively growing plants, to ‘Puck’ ssfor several physiological properties under low-temperature conditions. So far, the low-temperature tolerance of the mutants has been defined as the capacity to flower earlier under low temperature conditions (8—15°C) the wild type. All three lines were not chilling sensitive in the vegetative state and were able to acclimatize and to develop freezing tolerance. Differences between ‘Puck’ and the mutants were found but could not be related to the low-temperature tolerance of the mutants in the generative phase. Levels of the amino acid proline increased during the hardening process, reaching the highest level in the cultivar ‘Puck’. No evidence could be obtained that proline is causally involved in the cold-hardening process. Freezing-induced membrane injury was found to decrease with cold hardening (0—28 days) but the two mutants did not show a greater capacity to acclimatize and cold harden than the original cultivar ‘Puck’.     

Performance and Variability of Local Barley Landraces in Near-Eastern Environments

Homozygous lines from six Syrian and two Jordanian landrace populations were tested under highly productive growing conditions in Tel Hadia (1982/83), under drought stress in Breda (1983/84), and under dryland salinity stress in Hegla (1982/83/84) in Syria. Mean grain yield levels ranged between 260 kg/ha and 4850 kg/ha. Under drought and salinity stress, the majority of the landrace lines out-yielded the best cheeks significantly. In Tel Hadia the check cultivars mostly outyielded the landrace lines, but not always significantly. In all environments the harvest index of the landrace lines was near the optimum for barley. They expressed intermediate plant height and time to flowering, high lodging susceptibility under favorable growing conditions, high protein content, and a wide range of yield component combinations. In the stress environments highly significant genetic variation among the landrace lines was found. The heritabilities for gram yield were high in these trials. The correlations between performance under stress and under favorable growing conditions were poor. Therefore, the largest gains for variety improvement for the Syrian steppe area are expected from direct selection under stress conditions. Unique responses in proline accumulation and germination patterns in saline solution indicated specific adaptation in this material. These landraces, thus, are a useful source of breeding material, which also widens the genetic base of the present breeding program.     

Selection of hydroxyproline-resistant proline-accumulating mutants of cauliflower (brassica oleracea var. botrytis)

Summary A procedure is described by which hydroxyproline-resistant lines could be selected from regenerating curd tissue of cauliflower. Mutagenesis was by N-nitroso-N-ethylurea, supplied as a drop of 0.3 mM solution on each 3 mm diameter curd piece. The mutagen generated numerous morphological and pigment mutations without significantly affecting shoot regeneration from explants. Thirty one resistant shoots were recovered from more than six thousand explants mutagenised on regeneration medium supplemented with 3 mM hydroxyproline, while none was obtained from a similar number of non-mutagenised controls. Out of twenty-three resistant shoots which survived subculture, only one showed consistently elevated levels of endogenous proline. During early shoot culture passages, proline levels were 3.6–4.7 times higher than controls, but this was reduced to 1.6 times after 10–12 culture passages in the absence of hydroxyproline. Possible reasons for this decline are discussed. Leaf strip assays suggest resistant shoots may be chimeras and current efforts are directed towards regenerating solid mutants from resistant sectors. These will then be evaluated for any alteration in frost tolerance.Abbreviations IBA Indole-3-butyric-acid - NEU N-nitroso-N-ethylurea     

Evaluation of proline analysis and chlorophyll fluorescence quenching measurements as drought tolerance indicators in durum wheat (Triticum turgidum L. var. durum)

Summary The possibility of using proline accumulation and fluorescence inhibition as predictive tests for drought tolerance in durum wheat has been investigated. The drought susceptibility of 25 genotypes was evaluated by comparing yields and yield components in irrigated and non irrigated conditions in the field. A drought susceptibility index (DSI) was calculated based on yields from irrigated and dry treatments and compared with the results obtained using the two physiological criteria. Proline accumulation and chlorophyll fluorescence inhibition were found to be significantly and negatively correlated with DSI of grain yield, biological yield, and thousand kernel weight, and tiller index. The use of both criteria for breeding durum wheat in Mediterranean dryland is discussed.     

甘蔗和烟草幼叶原生质体分离前后的膜透性与脯氨酸含量的变化

甘蔗和烟草等幼叶经细胞壁降解酶水解细胞壁所获新鲜的原生质体的电解质外渗率和脯氨酸含量均有所提高，其中以野生蔗斑茅原生质体电解质外渗率最高，甘蔗原生质体的次之，烟草原生质体的最少；甘蔗原生质体的脯氨酸增量最高，斑茅原生质体的次之，烟草原生质体的最低。表明烟草原生质体受损程度低于甘蔗和斑芽等原生质体。     

Contribution of mineral nutrition to the response of barley seedlings to polyethylene glycol–induced mild water stress

The effect of polyethylene glycol–induced osmotic stress on the activity of nitrate reductase, glutamine synthetase, and glycolate oxidase in leaves of young barley plants grown under two nutrient‐supply regimes was studied. The activity of nitrate reductase gradually decreased after polyethylene glycol (PEG) application, while glutamine synthetase and glycolate oxidase were increased. It is speculated that the enhanced glutamine synthetase and glycolate oxidase activities are due to increased flux of metabolites through the photorespiratory cycle. Prominent increase in concentrations of free proline, reducing sugars, and free amino acids was observed. The possible contribution of these cellular solutes to the process of osmotic adjustment and the role of mineral supply is discussed. It is suggested that low N supply in combination with stress conditions switched the preferred osmolyte type from amino acids (N‐containing) to sugars (C‐containing).