查看更多>>摘要：Poor fruit set and growth are known to be caused by temperature stress in tomato cultivation. We focused on the effect of short-term temperature stress on each day during the five days before anthesis. The relationship between temperature stress and auxin-related factors was investigated using an experimental tomato cultivar, Micro-Tom expressing the auxin reporter DR5::GUS as a model system. While DR5::GUS expression in the control plants increased in ovaries and transferred to peduncles during the later developmental stages, that under high-temperature stress was not detected or very low. Some smaller fruit grew even under high-temperature stress probably due to the low level of DR5::GUS expression. Therefore, it was suggested that temporary high-temperature stress at any stage in this study affected the localization of auxin to ovaries and peduncles, and further affected fruit set and growth. By contrast, no decreased fruit set was observed with some delay and recovery of fruit growth under low-temperature stress, and this corresponded to the levels of DR5::GUS expression. The expression of GUS with the promoter of the tomato PIN gene, which is involved in the auxin transport, was not affected by high-temperature stress. On the other hand, the expression of ToFZY genes involved in auxin synthesis were affected by temperature stress, suggesting a part of the mechanism of the decrease in DR5::GUS expression under high-temperature stress.
查看更多>>摘要：Organ abscission is a developmental process regulated through changes in the abscission zone (AZ) and governed primarily by ethylene. In roses, the opening of flowers is also an ethylene-sensitive process possibly requiring changes at the AZ to facilitate petal movement. A study of the rose petal AZ transcriptome of the early-abscising fragrant rose, R. bourboniana, had indicated suppression of the jasmonic acid (JA) pathway in the AZ before abscission. Detailed investigation of 24 genes representing JA biosynthesis/perception /signalling revealed a rapid and substantial down-regulation of the entire JA pathway in the AZ prior to flower opening and abscission. Transcript levels of 17 genes encoding JA biosynthesis members of the PLD/LOX/AOS/AOC/OPR families and the receptor/signalling components of COI1/JAZ/MYC2/NINJA families decreased by 50-90% in petal AZ within 4 h of ethylene treatment as well as during natural field abscission (ethylene untreated). In contrast, R. hybrida flowers (which show delayed opening and abscission even after ethylene treatment) were much less affected in 10/24 genes while transcript levels of 9/24 JA pathway genes actually increased several fold during or just prior to abscission. JA treatment delayed flower opening as well as petal abscission by more than 24 h in R. bourboniana and also increased transcription of the JA pathway genes, unlike ethylene. The strong and rapid reduction of the entire JA pathway in the AZ in R. bourboniana flowers, prior to flower opening and petal abscission, suggests a negative role for JA in these processes with JA acting opposite to ethylene and possibly reducing ethylene sensitivity.
查看更多>>摘要：Unbalanced Calcium (Ca) and nitrogen (N) supply have been a struggle for apple fruit quality and yield. Calcium ion (Ca2+) and nitrate (NO3-) are two major forms of Ca and N absorbed by most terrestrial plants. The study was for investigating the effect of Ca2+ addition (5 and 10 mM) under different NO3- conditions (0, 5, 10, 15, 20, 25 mM) on M9T337 rootstocks phenotypes and their morphological, physiological, and related-genes differences in nutrient solution hydroponics. It was revealed from the study that independent variables significantly affected the plants growth. Relatively high NO3- plus less Ca2+ disturbed by different degrees of burned-down curling of rootstock leaves and root growth arrest. And Ca addition could relieve symptom caused by low and high N. The interaction of Ca and N increase their uptake by activating nitrate reductase (NR), glutamine synthetase (GS), Ca2+-ATPase and inducing CAM content, then up-regulating MdNRT1.1, MdNRT2.1, MdCDPK, and down-regulating MdACA expressions. Moreover, under lower-N (10 mM), moderate Ca (5 mM) could ensure optimal growth and development. And under higher-N (20 mM), more Ca (10 mM) was the most optimal, which was significantly different from other Ca2+ level (P < 0.05). Ultimately, maintaining a proper balance between N (0.01966-0.0303 kg kg(-1)) and Ca (0.0091-0.0141 kg kg(-1)) in leaves is important for developing desired apple rootstocks. Collectively, our data revealed that lower-N plus optimal Ca and higher-N plus more Ca could ensure better growth and improve their uptake efficiency, which would provide a scientific basis for rational fertilization and scientific management in extensive apple orchards.
查看更多>>摘要：Silicon can enhance plant resistance to biotic stress by directly inhibiting pathogens, forming physical barriers, and inducing the synthesis of defense compounds. However, no study is available on silicon on fruit wound healing. Here, we found that sodium silicate enhanced the activities of phenylalanine ammonia-lyase, 4-coumarate coenzyme A ligase, and cinnamate-4-hydroxylase, and elevated levels of cinnamic, rho-coumaric, caffeic, ferulic, sinapic acids, and total phenols at fruit wounds. Sodium silicate accelerated the deposition of suberin poly phenolic and silicon at wounds, increased the hardness and brittleness and reduced their resilience of the healing tissues, which slowed weight loss by wounded fruit, and disease index in fruit subjected to Trichothecium roseum. Taken together, sodium silicate may promote wound healing in muskmelons by activating phenylpropanoid pathway, accelerating suberin poly phenolic and silicon deposition at wounds, and increasing the hardness and brittleness of healing tissues.
查看更多>>摘要：Watercress (Nasturtium officinale R. Br.) is a highly nutritious leafy crop with a rich health-related phytonutrient profile including secondary plant metabolites such as glucosinolates. This semi-aquatic crop is well-suited for indoor hydroponic cultivation and has a growing market for its distinctive peppery taste and health benefits. We describe crop trials in three contrasting environments and report the changes to plant morphology, yield, and nutritional profile under varying blue light treatments. Yield and glucosinolate quantity were significantly increased in a vertical farm system enriched in blue light, relative to field-grown crops. Additionally, PBITC, a glucosinolate not previously identified in field-grown watercress, was found in plants grown in a vertical farm. This work demonstrates the great potential of watercress in a new era of controlled environment agriculture to deliver improved health benefits to customers.
Gonzalez-Hernandez, Ana IsabelPerez-Sanchez, RodrigoPlaza, JavierMorales-Corts, M. Remedios...
9页
查看更多>>摘要：Compost teas (CTs) are organic extracts originated by mixing mature compost with tap water under controlled conditions. The application of these extracts could constitute a biostimulant and eco-friendly alternative for sustainable agriculture. Thus, this study was proposed to verify the contribution of different doses and Trichoderma-fortified green waste based-CT in plant susceptibility against Rhizoctonia solani infection, as well as in plant growth and tuber quality in two potato cultivars (Agria and Hermes) grown under greenhouse and field conditions. The results showed that CT-treated plants displayed a higher resistance to Rhizoctonia solani, being Hermes the most susceptible cultivar. Moreover, CT-treated plants showed an enhancement in yield, shoot number, tuber weight and tuber size, as well as an advance in potato sprouting, especially in those plants treated with the highest CT dose. A similar trend was observed in both cultivars. Furthermore, to confirm the effect of CT on sprouting, an additional study in the laboratory was carried out with Agria cultivar, in which it was observed that the advance in the crop cycle is induced by CT supply. Subsequently, the fried-quality parameters of tubers coming from potato plants grown under the different treatments in field conditions were studied. The addition of CT to potato plants reduced fried defects, total soluble solids in tubers, while increasing moisture content. However, both cultivars displayed several differences under control conditions, since Agria displayed high fried defects, as well as a reduction in total soluble solids and in the slice puncture test. Therefore, the application of CT is a dose-dependent effective approach to decrease R. solani attack, advance potato cycle and promote plant growth, as well as to obtain a better fried-quality tuber that is highly valued by the agri-food industries.
查看更多>>摘要：Kiwifruit (Actinidia deliciosa cv. Hayward) was exposed to high O-2/N-2 controlled atmosphere (30 % O-2 + 70 % N-2) for 7 d at 23 +/- 1 degrees C to evaluate the effects on postharvest ripening and fruit quality. The treated fruit exhibited a dramatic increase in soluble solids content (SSC) and a rapid decrease in firmness and titratable acidity (TA), accompanied by a noticeable change in flesh color and volatile organic compounds during the first 7 d. Fruit exposed to high oxygen concentration required 7 d to reach the edible firmness (similar to 10 N), while the control fruit needed 42 d. At edible firmness, no differences in the SSC, TA, and flesh color were observed between treated and untreated kiwifruit, although the concentration and amounts of volatile organic compounds showed a little difference. High O-2/N-2 controlled atmosphere advanced respiration rate peak, with an increase in the contents of adenosine triphosphate (ATP), adenosine diphosphate (ADP), and adenosine monophosphate (AMP). The treatment also increased catalase (CAT) and peroxidase (POD) activities. Quantitative real-time PCR revealed increased expression levels of AdAAC1, AdAOX2, AcEXP1, AcPL1, AcPG, AcACS, AcACO, and AcACO2 in the treated fruit. Thus, the study's results indicate that high O-2/N-2 controlled atmosphere could accelerate kiwifruit ripening and result in good fruit quality.
查看更多>>摘要：The role of selenium (Se) in mitigating detrimental effects of drought stress on the plants has been reported, but the mechanism is still unclear. In this study, the function of Se fertilization on tomato (Solanum lycopersicum L.) under drought stress was characterized. Our results showed that the growth reduction caused by drought stress was alleviated by application of exogenous Se to a large extent. In addition, the treatment of Se significantly increased the net photosynthetic rate (Pn), transpirational rate (Tr), stomatal conductance (Gs) and water use efficiency (WUE) than in the absence of Se under drought stress treatment. Se addition also significantly inhibited the increase of malondialdehyde (MDA), soluble sugar and proline levels of tomato leaves and produced less reactive oxygen species (ROS) accumulation under drought stress. Furthermore, Se supplementation to the nutrient solution significantly increased the endogenous salicylic acid (SA) and methylated SA (MeSA) levels in tomato roots and promoted the conversion from SA to MeSA in tomato leaves under drought stress conditions via regulating the expression levels of several genes involved in SA biosynthesis and conversion such as PAL1, ICS, SAMT and SABP2. But the pretreatment with ABT (1-aminobenzotriazole, a SA inhibitor) abolished the beneficial effect of Se on drought stress tolerance of plants. These results suggested that Se application promoted photosynthetic efficiency and plant growth, alleviated drought-induced oxidative stress, and increased the endogenous SA levels, thereby imparting drought stress tolerance of tomato plants. This study may provide a theoretical basis for utilization of Se fertilizer to improve the yield and quality of agricultural products under stress.
查看更多>>摘要：Apricots softening senescence is a complex metabolic network, and these metabolic pathways coordinate with each other to make aging irreversible. To identify and implement treatments to delay ripening senescence in apricots, the effects of salicylic acid (SA) treatment on ethylene biosynthesis and cell wall degradation were investigated during 35 days of storage at 4 & nbsp;C and 90%-95% relative humidity. In contrast with control, SA treatment suppressed ethylene production due to inhibited ACC synthase (ACS) and ACC oxidase (ACO) activities and reduced 1-aminocyclopropane-1-carboxylic acid (ACC) content. Furthermore, the decreases in fruit firmness, contents of CDTA-soluble pectin (CSP), Na2CO3-soluble pectin (NSP), hemicellulose as well as cellulose, and the increase in water-soluble pectin (WSP) of the apricots could be delayed by SA treatment. Enzyme activities of cellulase (EC 3.2.1.4), beta-glucosidase (EC 3.2.1.21), polygalacturonase (PG; EC 3.2.1.15), pectin methylesterase (PME; EC 3.1.1.11) as well as PaPG1 and PaPME1 gene expressions were suppressed strongly by SA treatment and these two genes were closely correlated with fruit softening. In addition, transmission electron microscopy (TEM) images demonstrated that the softening process of SA-treated apricots could be delayed efficiently and preventing structural breakdown. These results suggest that cell wall degrading enzyme activities are regulated by ethylene, and SA treatment mitigated apricots softening by inhibiting ethylene biosynthesis and decreasing cell degrading enzyme activities.
查看更多>>摘要：There is little information on the impact of agrometeorological factors on late-maturing citrus varieties. Here, several indices of the agronomic and physiological quality of 'Orah' mandarin fruit during three consecutive years were studied along with the metabolic traits under different climatic conditions. The average yield was high in the dry-hot valleys. However, the yield and yield efficiency were the lowest in areas with humid-sparse sunlight. The fruit in the dry-hot valleys and south subtropical regions were large and had seed number beyond 15.38, while the fruit in areas with humid-sparse sunlight were reddish and had few seeds. A statistical analysis of the total soluble solids (TSS) within three years showed that the fruit with highest amounts were in the mid subtropical regions (> 14.03%), followed by the dry-hot valleys. The fruit of tropical rainforest areas (titratable acid > 0.67%) were considered to contain the highest percentage of acid. A metabolic analysis showed that the contents of several metabolites, such as malic acid and proline, varied noticeably across different climatic regions. Correlation and factor analyses of the agronomic, physiological and metabolic indices with meteorological parameters revealed that the fruit yield and quality in the dry-hot valleys were superior to those observed in other regions and that temperature, in particular at the degreening and overwintering stages, along with the hours of sunshine significantly resulted in a considerable degree of variation in the indicators of fruit heterogeneity, such as weight, TSS, malic acid and proline.
NSTL
Elsevier