Soybean Temperature Research Articles

Soybean phenological changes in response to climate warming in three northeastern provinces of China

ContextSoybean plays an important role in agricultural production in three northeastern provinces of China; furthermore, climate change, particularly temperature and rainfall changes, can significantly regulate soybean phenological periods. Research QuestionCurrent research on the spatial and temporal characteristics of soybean phenology and its relationship with climate change in the three northeastern provinces of China is still inadequate. MethodsIn this study, phenological and meteorological data from 26 agrometeorological stations in northeastern China were used to evaluate temporal and spatial changes and their correlations with soybean temperature, rainfall, phenological stage, and growth duration over the long term in three northeastern provinces. ResultsOn average, 22 of the 26 stations showed increases in temperature, and 15 stations showed increases in rainfall during the survey stage. All of soybean growth nodes were delayed, except R8, which advanced by 0.28 days, and all soybean growth durations were shortened except for during the V3-R1 period. In addition, temperature was negatively correlated with growth duration, while rainfall was positively correlated with growth duration. Further, the spatial and temporal distribution of temperature and rainfall showed that an increase in temperature led to an increase in thermal conditions and a significant northward and eastward expansion of the cumulative temperature zone, with the most significant increase in temperature occurring in most areas of Heilongjiang, followed by Liaoning. ConclusionsSoybean planting practices in the three eastern provinces should be adjusted to medium- and late-maturing varieties, which can adapt to climate change and mitigate its effects during the phenological period, due their tolerance to high heat. SignificanceThese findings fill a knowledge gap for understanding the relationship between soybean phenological changes and climate change in the three northeastern provinces.

Diverse flowering responses subjecting to ambient high temperature in soybean under short-day conditions.

Flowering time is one of important agronomic traits determining the crop yield and affected by high temperature. When facing high ambient temperature, plants often initiate early flowering as an adaptive strategy to escape the stress and ensure successful reproduction. However, here we find opposing ways in the short-day crop soybean to respond to different levels of high temperatures, in which flowering accelerates when temperature changes from 25 to 30 °C, but delays when temperature reaches 35 °C under short day. phyA-E1, possibly photoperiodic pathway, is crucial for 35 °C-mediated late flowering, however, does not contribute to promoting flowering at 30 °C. 30 °C-induced up-regulation of FT2a and FT5a leads to early flowering, independent of E1. Therefore, distinct responsive mechanisms are adopted by soybean when facing different levels of high temperatures for successful flowering and reproduction.

Inoculation with Arbuscular Mycorrhizal Fungi Alleviates the Adverse Effects of High Temperature in Soybean.

High temperature is foremost abiotic stress and there are inadequate studies explicating its impact on soybean. In this study, a pot experiment was done in a greenhouse maintained at a day/night temperature of 42/28 °C with a mean temperature of 35 °C to examine the effects of high temperature in soybean plants inoculated with and without arbuscular mycorrhizal fungi (AMF).Various parameters were taken in soybean plants treated with AMF (+) and AMF (−) such as growth analysis, chlorophyll content, canopy temperature, number of stomata, gas exchange, chlorophyll fluorescence, seed yield, and its attributes. It was observed that growth parameters like leaf area, stem height, root length, shoot and root dry biomass were increased in AMF (+) as compared to AMF (−) plants. Chlorophyll content, the number of stomata, photosynthesis rate, stomatal conductance, transpiration rate, and water use efficiency increased in AMF (+) as compared to AMF (−) plants. Chlorophyll fluorescence parameters such as Fv/Fm, Fv/Fo, PhiPSII, fluorescence area, performance index, photochemical quenching, linear electron transport rate, and active reaction centres density of PSII were also found to be enhanced in AMF (+) plants. However, canopy temperature, intercellular CO2, Fo/Fm, and non-photochemical quenching were higher in AMF (−) as compared to inoculated plants. An increase in growth and photosynthesis ultimately enhanced the seed yield and its attributes in AMF (+) as compared to AMF (−). Thus, AMF (+) plants have shown much better plant growth, photosynthesis parameters, and seed yield as compared to AMF (−) plants under high temperature. Thus, it is concluded that heat stress-induced damage to the structure and function of the photosynthetic apparatus was alleviated by AMF inoculum. Therefore, AMF can be used as a biofertilizer in alleviating the adverse effects of heat stress in soybean.

Identification of quantitative trait loci associated with canopy temperature in soybean

A consistent risk for soybean (Glycine max L.) production is the impact of drought on growth and yield. Canopy temperature (CT) is an indirect measure of transpiration rate and stomatal conductance and may be valuable in distinguishing differences among genotypes in response to drought. The objective of this study was to map quantitative trait loci (QTLs) associated with CT using thermal infrared imaging in a population of recombinant inbred lines developed from a cross between KS4895 and Jackson. Heritability of CT was 35% when estimated across environments. QTL analysis identified 11 loci for CT distributed on eight chromosomes that individually explained between 4.6 and 12.3% of the phenotypic variation. The locus on Gm11 was identified in two individual environments and across environments and explained the highest proportion of phenotypic variation (9.3% to 11.5%) in CT. Several of these CT loci coincided with the genomic regions from previous studies associated with canopy wilting, canopy temperature, water use efficiency, and other morpho-physiological traits related with drought tolerance. Candidate genes with biological function related to transpiration, root development, and signal transduction underlie these putative CT loci. These genomic regions may be important resources in soybean breeding programs to improve tolerance to drought.

The Floral Repressor GmFLC-like Is Involved in Regulating Flowering Time Mediated by Low Temperature in Soybean

Soybean is an important crop that is grown worldwide. Flowering time is a critical agricultural trait determining successful reproduction and yields. For plants, light and temperature are important environmental factors that regulate flowering time. Soybean is a typical short-day (SD) plant, and many studies have elucidated the fine-scale mechanisms of how soybean responds to photoperiod. Low temperature can delay the flowering time of soybean, but little is known about the detailed mechanism of how temperature affects soybean flowering. In this study, we isolated GmFLC-like from soybean, which belongs to the FLOWERING LOCUS C clade of the MADS-box family and is intensely expressed in soybean leaves. Heterologous expression of GmFLC-like results in a delayed-flowering phenotype in Arabidopsis. Additional experiments revealed that GmFLC-like is involved in long-term low temperature-triggered late flowering by inhibiting FT gene expression. In addition, yeast one-hybrid, dual-luciferase reporter assay, and electrophoretic mobility shift assay revealed that the GmFLC-like protein could directly repress the expression of FT2a by physically interacting with its promoter region. Taken together, our results revealed that GmFLC-like functions as a floral repressor involved in flowering time during treatments with various low temperature durations. As the only the FLC gene in soybean, GmFLC-like was meaningfully retained in the soybean genome over the course of evolution, and this gene may play an important role in delaying flowering time and providing protective mechanisms against sporadic and extremely low temperatures.

13 ダイズとワタにおける蒸散、受光量、葉温の関係について

13 ダイズとワタにおける蒸散、受光量、葉温の関係について

大豆の障害型冷害に関する研究 : 第2報 開花前後の低温が花粉及び受粉に与える影響

大豆の障害型冷害に関する研究 : 第2報 開花前後の低温が花粉及び受粉に与える影響

大豆の障害型冷害に関する研究 : 第1報 開花前後の低温下における開花習性

大豆の障害型冷害に関する研究 : 第1報 開花前後の低温下における開花習性

Glyma11g13220, a homolog of the vernalization pathway gene VERNALIZATION 1 from soybean [Glycine max (L.) Merr.], promotes flowering in Arabidopsis thaliana.

BackgroundThe precise timing of flowering is fundamental to successful reproduction, and has dramatic significance for crop yields. Although prolonged low temperatures are not required for flowering induction in soybean, vernalization pathway genes have been retained during the evolution of this species. Little information is currently available in regarding these genes in soybean.ResultsWe were able to detect the expression of Glyma11g13220 in different organs at all monitored developmental stages in soybean. Glyma11g13220 expression was higher in leaves and pods than in shoot apexes and stems. In addition, Glyma11g13220 was responsive to photoperiod and low temperature in soybean. Furthermore, Glyma11g13220 was found to be a nuclear-localized protein. Over-expression of Glyma11g13220 in an Arabidopsis Columbia-0 (Col-0) background resulted in early flowering. Quantitative real-time PCR analysis revealed that transcript levels of flower repressor FLOWERING LOCUS C (FLC), and FD decreased significantly in transgenic Arabidopsis compared with wild-type Col-0, while the expression of VERNALIZATION INSENSITIVE 3 (VIN3) and FLOWERING LOCUS T (FT) noticeably increased.ConclusionsOur results suggest that Glyma11g13220, a homolog of Arabidopsis VRN1, is a functional protein. Glyma11g13220, which is responsive to photoperiod and low temperature in soybean, may participate in the vernalization pathway in Arabidopsis and help regulate flowering time. Arabidopsis VRN1 and Glyma11g13220 exhibit conserved as well as diverged functions.Electronic supplementary materialThe online version of this article (doi:10.1186/s12870-015-0602-6) contains supplementary material, which is available to authorized users

QTL Identification of the Insensitive Response to Photoperiod and Temperature in Soybean by Association Mapping

The insensitive response to photoperiod and temperature is an important quantitative trait for soybean in wide adaptation breeding. The natural variation in response to photoperiod and temperature was detected using 275 accessions of soybean [Glycine max (L.) Merrill] from China. Genome-wide association mapping, based on population structure analysis, was carried out using 118 SSR markers by the TASSEL GLM (general linear model) program. Nine SSR markers (P<0.01) were associated with the value of the response to photoperiod and temperature (VRPT) caused by days to flowering (DF), among which, Satt308 (LG M), Satt150 (LG M) and Satt440 (LG I), were identified in both 2006 and 2007. Twelve SSR markers (P<0.01) were associated with VRPT caused by days to maturity (DM), among which three markers, Satt387 (LG N), Satt307 (LG C2) and AW310961 (LG J), were detected in both 2006 and 2007. In addition, a total of 20 elite alleles were screened out over 2006 and 2007 for being associated with an insensitive response to photoperiod and temperature (IRPT) caused by DF and a total of seven different elite alleles were screened out for being associated with IRPT caused by DM. Among these elite alleles, five alleles, Satt150-244, Satt308-164, Satt308-206, Satt440-176, and Satt440-206, were associated with IRPT caused by DF and were identified in both years, but only one allele, Satt307-170, was identified as being associated with an IRPT caused by DM. Based on these elite alleles, a set of typical accessions were screened out. The result about the genetic basis of IRPT is meaningful for soybean wide adaption breeding.

Intercepted solar radiation affects oil fatty acid composition in crop species

Solar radiation intercepted during grain filling affects growth of grain crops. Its effects on oil fatty acid composition have not been investigated. The objective of this work was to investigate the effect of intercepted solar radiation per plant on oil fatty acid composition in four crops. An experiment including a cultivar of soybean, maize and sunflower was sown at Balcarce, Argentina, during two growing seasons (2001–02 and 2004–05) and two experiments with a rape cultivar were conducted during in 2004 and 2005. The amount of intercepted solar radiation during grain filling was modified by shading (50–80%) and thinning plants (50%). In addition, the same cultivars of soybean and maize were sown in the field at Paraná, Argentina, during the 2004–05 growing season and in growth chambers under different day/night temperatures during grain filling. Regardless of the species, oleic acid percentage increased as intercepted solar radiation (ISR) per plant increased. The highest difference (13%) was observed in sunflower (shading vs. thinning) and the increase in oleic acid was associated with a reduction in both linoleic and linolenic acids. Saturated fatty acid percentage was not affected by intercepted solar radiation per plant. Differences among radiation treatments were observed not only at physiological maturity but also at earlier stages of the grain filling period. In soybean and maize, increasing daily mean temperature increased oleic acid percentage ( r 2 ≥ 0.52). Changes in fatty acid composition in radiation experiments and treatments were not accounted for by variations in temperature (differences among treatments were ≤1 °C). In sunflower and maize, the source (ISR)–sink (grain number) ratio during the grain filling period better explained changes in oleic acid percentage than per plant ISR alone. Changes in fatty acid composition due to radiation treatments were as large as variations produced by changes in temperature in soybean and maize, but not in sunflower. Based on these results, management practices that increase intercepted radiation by the plant during grain filling could contribute to obtain oils with higher oleic acid percentage.

A novel major quantitative trait locus controlling seed development at low temperature in soybean (Glycine max)

Low temperature is among the critical environmental factors that limit soybean production. To elucidate the genetic basis for chilling tolerance and identify useful markers, we conducted quantitative trait loci (QTL) analysis of seed-yielding ability at low temperature in soybean (Glycine max), using artificial climatic environments at usual and low temperatures and recombinant inbred lines derived from a cross between two contrasting cultivars in terms of chilling tolerance. We identified a QTL of a large effect (LOD > 15, r (2) > 0.3) associated with seed-yielding ability only at low temperature. The QTL was mapped near marker Sat_162 on linkage group A2, where no QTL for chilling tolerance has previously been identified. The tolerant genotype did not increase the pod number but maintained the seed number per pod and single seed weight, namely, the efficiency of seed development at low temperature. The effect of the QTL was confirmed in a segregating population of heterogeneous inbred families, which provided near-isogenic lines. The genomic region containing the QTL also influenced the node and pod numbers regardless of temperature condition, although this effect was not primarily associated with chilling tolerance. These results suggest the presence of a new major genetic factor that controls seed development specifically at low temperature. The findings will be useful for marker-assisted selection as well as for understanding of the mechanism underlying chilling tolerance in reproductive organs.

Effects of elevated CO2 and temperature on photosynthesis and Rubisco in rice and soybean

ABSTRACTRice (Oryza sativa L. cv. IR‐72) and soybean (Glycine max L. Merr. cv. Bragg), which have been reported to differ in acclimation to elevated CO2, were grown for a season in sunlight at ambient and twice‐ambient [CO2], and under daytime temperature regimes ranging from 28 to 40°C. The objectives of the study were to test whether CO2 enrichment could compensate for adverse effects of high growth temperatures on photosynthesis, and whether these two C3 species differed in this regard. Leaf photosynthetic assimilation rates (A) of both species, when measured at the growth [CO2], were increased by CO2 enrichment, but decreased by supraoptimal temperatures. However, CO2 enrichment more than compensated for the temperature‐induced decline in A. For soybean, this CO2 enhancement of A increased in a linear manner by 32–95% with increasing growth temperatures from 28 to 40°C, whereas with rice the degree of enhancement was relatively constant at about 60%, from 32 to 38°C. Both elevated CO2 and temperature exerted coarse control on the Rubisco protein content, but the two species differed in the degree of responsiveness. CO2 enrichment and high growth temperatures reduced the Rubisco content of rice by 22 and 23%, respectively, but only by 8 and 17% for soybean. The maximum degree of Rubisco down‐regulation appeared to be limited, as in rice the substantial individual effects of these two variables, when combined, were less than additive. Fine control of Rubisco activation was also influenced by both elevated [CO2] and temperature. In rice, total activity and activation were reduced, but in soybean only activation was lowered. The apparent catalytic turnover rate (Kcat) of rice Rubisco was unaffected by these variables, but in soybean elevated [CO2] and temperature increased the apparent Kcat by 8 and 22%, respectively. Post‐sunset declines in Rubisco activities were accelerated by elevated [CO2] in rice, but by high temperature in soybean, suggesting that [CO2] and growth temperature influenced the metabolism of 2‐carboxyarabinitol‐1‐phosphate, and that the effects might be species‐specific. The greater capacity of soybean for CO2 enhancement of A at supraoptimal temperatures was probably not due to changes in stomatal conductance, but may be partially attributed to less down‐regulation of Rubisco by elevated [CO2] in soybean than in rice. However, unidentified species differences in the temperature optimum for photosynthesis also appeared to be important. The responses of photosynthesis and Rubisco in rice and soybean suggest that among C3 plants species‐specific differences will be encountered as a result of future increases in global [CO2] and air temperatures.

大豆の障害型冷害に関する研究 : 第3報 低温下の着莢数の変動

大豆の障害型冷害に関する研究 : 第3報 低温下の着莢数の変動

Effects of elevated CO2 and temperature on development in soybean and five weeds

Developmental rates of soybean [Glycine max (L.) Merr. 'Braxton'], johnsongrass [Sorghum halepense (L.) Pers.], quackgrass [Elytrigia repens (L.) Nevski], redroot pigweed (Amaranthus retroflexus L.), sicklepod (Cassia obtusifolia L.), and velvetleaf (Abutilon theophrasti Medic.) were compared among plants grown in all combinations of two temperature levels (avg. day/night of 26/19 °C and 30/23 °C) and two CO2 levels (350 and 700 ppm). Neither temperature nor CO2 affected johnsongrass tillering rate, but plants began tillering earlier at higher temperatures. Adverse effects of higher temperatures on quackgrass development were alleviated by elevated CO2 conditions. Plastochron rate was higher at higher temperatures in all dicot species (soybean, redroot pigweed, sicklepod, and velvetleaf), and was higher at elevated CO2 in all dicots except velvetleaf. Calculating plastochron rates on a degree day basis removed differences between temperature treatments, but did not affect responses to CO2. Responses of dicot branch and branch leaf production to treatments varied among species. Branch production per day increased with higher temperatures in redroot pigweed, decreased with higher temperatures in sicklepod, and was unaffected by temperature in soybean. The relationship between main axis and branch developmental rates was altered by temperature in soybean, and by both temperature and CO2 in sicklepod, but was unaffected by either treatment in redroot pigweed. These results indicate that developmental responses to temperature and CO2 depend on both the species and the aspect of development being considered. Key words: Plastochron index, CO2 by temperature interaction, johnsongrass, quackgrass, redroot pigweed, sicklepod, velvetleaf

Intracellular redistribution of phytochrome in etiolated soybean (Glycine max L.) seedlings

The intracellular distribution of phytochrome in hypocotyl hooks of etiolated soybean (Glycine max L.) has been examined by immunofluorescence using a newly produced monoclonal antibody (Soy-1) directed to phytochrome purified from etiolated soybean shoots. Cortical cells in the hook region exhibit the strongest phytochrome-associated fluorescence, which is diffusely distributed throughout the cytosol in unirradiated, etiolated seedlings. A redistribution of immunocytochemically detectable hytochrome to discrete areas (sequestering) following irradiation with red light requires a few minutes at room temperature in soybean, whereas this redistribution is reversed rapidly following irradiation with far-red light. In contrast, sequestering in oat (Avena sativa L.) occurs within a few seconds (D. McCurdy and L. Pratt, 1986, Planta 167, 330-336) while its reversal by far-red light requires hours (J. M. Mackenzie Jr. et al., 1975, Proc. Natl. Acad. Sci. USA 72, 799-803). The time courses, however, of red-light-enhanced phytochrome pelletability and sequestering are similar for soybean as they are for oat. Thus, while these observations made with a dicotyledon are consistent with the previous conclusion derived from work with oat, namely that sequestering and enhanced pelletability are different manifestations of the same intracellular event, they are inconsistent with the hypothesis that either is a primary step in the mode of action of phytochrome.

Responses of photosynthesis to irradiance and temperature in soybean, Glycine max (L.) Merr

The response of photosynthesis to irradiance and temperature during growth was investigated in two soybean genotypes. Soybean is a species that can modify its structure and metabolism so as to adapt to differing light conditions; its responses to rapid changes in irradiance are characterized by their flexibility. However, the temperature during growth can change the response to irradiance: moreover, there may be a marked interaction with genotype.The response of photosynthesis to irradiance consists of changes in leaf thickness, which bring about variations in the mesophyll resistance to CO2 transfer. The increase in net photosynthesis per unit of leaf area is due to the increase in the amount of assimilating material beneath unit of area, as corroborated by the stability of the net photosynthesis per unit volume. Moreover, the response of photosynthesis to temperature is due to the mesophyll diffusion 'constant' which decreases with the growth temperature.