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Simple regulation of c-Jun N-terminal kinase (JNK) or p38 mitogen-activated protein kinase (MAPK) pathways is not enough to trigger cell apoptosis. However, activation of the stress activated pathway (JNK/p38 MAPK) together with inhibition of the growth factor activated extracellular signal-regulated kinase (ERK) pathway can promote cell apoptosis. We hypothesized that inhibition of the JNK or p38 pro-apoptotic pathway and activating the ERK pathway could be the mechanism of anti-apoptosis following cerebral ischemia/reperfusion injury. To investigate the mechanism of the protective effect of electroacupuncture on cerebral ischemia/reperfusion injury in JNK knockout mice, mouse models of cerebral ischemia/reperfusion injury were established by Longa’s method. Electroacupuncture was conducted at acupoints Chize (LU5), Hegu (LI4), Sanyinjiao (SP6) and Zusanli (ST36) 1.5 hours after ischemia/reperfusion injury for 20 minutes, once a day. The neurological function was evaluated using neurological deficit scores. The expression of phospho-extracellular signal-regulated kinase (p-ERK) and phospho-p38 (p-p38) in JNK knockout mice was detected using double-labeling immunofluorescence and western blot assay. The mRNA expression of ERK and p38 was measured by quantitative real-time polymerase chain reaction. Electroacupuncture improved neurological function, increased the immunoreactivity and relative expression of p-ERK and reduced that of p-p38 in the cerebral cortex and hippocampus on the injured side. Electroacupuncture increased mRNA expression of ERK, but decreased that of p38 in the cerebral cortex and hippocampus on the injured side. In conclusion, electroacupuncture upregulated the protective ERK pathway and inhibited the pro-apoptotic p38 pathway, thereby exerting a neuroprotective effect and improving the neurological function in JNK knockout mice.

Objective To explore the effects of electroacupuncture (EA) on the phosphorylated extracellular signal regulated kinase (p-ERK) pathway of the cerebral cortex in a rat model of focal cerebral ischaemia/reperfusion (I/R). Methods 160 adult Sprague-Dawley rats underwent middle carotid artery occlusion (MCAO) to establish I/R injury and were randomly divided into four groups (n=40 each) that remained untreated (I/R group) or received EA at LU5, LI4, ST36 and SP6 (I/R+EA group), the ERK inhibitor PD98059 (I/R+PD group), or both interventions (I/R+PD+EA groups). An additional 40 rats undergoing sham surgery formed a healthy control group. Eight rats from each group were sacrificed at the following time points: 2 hours, 6 hours, 1 day, 3 days and 1 week. Neurological function was assessed using neurological deficit scores, morphological examination was performed following haematoxylin-eosin staining of cortical tissues, and apoptotic indices were calculated after terminal deoxyribonucleotidyl transferase (TdT)-mediated biotin-16-dUTP nick-end labelling. Cortical protein and mRNA expression of p-ERK and ERK were measured by immunohistochemistry and real-time quantitative PCR, respectively. Results Compared with the I/R group, neurological deficit scores and apoptotic indices were lower in the I/R+EA group at 1 and 3 days, whereas mRNA/protein expression of ERK/p-ERK was higher in the EA group at all time points studied. Conclusion Our results suggest that EA can alleviate neurological deficits and reduce cortical apoptosis in rats with I/R injury. These anti-apoptotic effects may be due to upregulation of p-ERK. Moreover, apoptosis appeared to peak at 1 day after I/R injury, which might therefore represent the optimal time point for targeting of EA.

Endoglucanase secreted by the fungus Trichoderma atroviride is a kind of cellulase. An endoglucanase gene egII was cloned from T. atroviride AS3.3013 and expressed in Saccharomyces cerevisiae INVScI. The open reading frame of the egII gene was composed of 1257 bp, encoding 418 amino acids with a molecular weight of 44.23 kDa plus a signal peptide of 21 amino acids. Based on sequence similarity, TaEGII belonged to the glycosyl hydrolase family 5. Expression of the egII gene in T. atroviride AS3.3013 can be induced by microcrystalline cellulose (MCC), bran, carboxymethyl cellulose (CMC), rice straw, and corn stalk but is inhibited by glucose. A highly efficient integrated expression vector (pYPIGH-B includes a sequence of the α-mating factor signal peptide (MF-α)) was constructed. The enzymatic activity of the supernatant of recombinant yeast YPIGH-B3 was 1.29 times higher than that of YES2-egII, demonstrating that the MF-α can significantly improve the expression of the recombinant EGII in S. cerevisiae. The recombinant endoglucanase TaEGII produced by S. cerevisiae showed maximum activity at pH 5.0 and temperature 60 °C. Under these conditions, the Km and Kcat values for Avicel and raffinose hydrolysis were 1.22 × 10–2 mg ml−1, 9.09 × 10−2 s−1 and 1.06 × 10–2 mg ml−1 , 9.18 × 10–2 s−1, respectively. The enzymatic activity of recombinant TaEGII was stable when incubated from 40 to 60 °C for 1 h. It was stable in a wide range of pH (4.0–7.0) and sensitive to various metal ions. Transgenic yeast strain YPIGH-B3 might be applied to cellulosic ethanol production.

In order to study the survival mechanisms to drought stress for fruit body of Auricularia auricula, soluble carbohydrates and respiratory enzymes were investigated. Fruit bodies were exposed to sunlight and were naturally dehydrated. Samples were taken at different levels of water loss (0%, 10%, 30%, 50% and 70%) to measure the content of soluble sugars and polysaccharides. The activities of phosphoglucose isomerase (PGI), combined glucose-6-phosphate dehydrogenase (G-6-PDH) and 6-phosphogluconate dehydrogenase (6-PGDH), and malate dehydrogenase (MDH), were also determined. The results showed that with the increase in water loss, soluble sugars and MDH activity declined, whereas the activities of G-6-PDH and 6-PGDH increased. Soluble polysaccharides content and PGI activity decreased with water loss up to 30% and increased afterwards. These results suggested that the pentose phosphate pathway (PPP), as demonstrated by activities of G-6-PDH and 6-PGDH, could be one of the mechanisms for survival during drought stress in the fruit body of A. auricula. Moreover, soluble polysaccharides may play a part in protecting the fruit body in further drought stress.

The rice low phytic acid (lpa) mutant Os-lpa-XS110-1(XS-lpa) has ~45 % reduction in seed phytic acid (PA) compared with the wild-type cultivar Xiushui 110. Previously, a single recessive gene mutation was shown to be responsible for the lpa phenotype and was mapped to a region of chromosome 3 near OsMIK (LOC_Os03g52760) and OsIPK1 (LOC_Os03g51610), two genes involved in PA biosynthesis. Here, we report the identification of a large insert in the intron of OsMIK in the XS-lpa mutant. Sequencing of fragments amplified through TAIL-PCRs revealed that the insert was a derivative of the LINE retrotransposon gene LOC_Os03g56910. Further analyses revealed the following characteristics of the insert and its impacts: (1) the inserted sequence of LOC_Os03g56910 was split at its third exon and rejoined inversely, with its 5' and 3' flanking sequences inward and the split third exon segments outward; (2) the LOC_Os03g56910 remained in its original locus in XS-lpa, and the insertion probably resulted from homologous recombination repair of a DNA double strand break; (3) while the OsMIK transcripts of XS-lpa and Xiushui 110 were identical, substantial reductions of the transcript abundance (~87 %) and the protein level (~60 %) were observed in XS-lpa, probably due to increased methylation in its promoter region. The above findings are discussed in the context of plant mutagenesis, epigenetics and lpa breeding.

The objectives of this study were to analysis the differences of microbial community diversity between the microbial additives (MA) compost and natural compost and the distribution (spatial and temporal) of MA during high-temperature composting by PCR-DGGE technology. The results showed that the MA started temperature rapidly; prolonged the time of maintained high-temperature process and increased the diversity of microbial than natural compost. Sequence comparison revealed that the microorganisms most belonged to uncultivable, thermophilic bacteria. Bacillus became the dominant microorganisms after mixed with MA. MA were found in the top and middle portions of the compost throughout nearly the entire composting process,but absent in the natural compost. Our finding represents an important step towards the understanding of MA and its function in the degradation process of compost.

In order to study the effects of long-term different fertilization on microbial community functional diversity in arable black. soil, we examined microbial metabolic activities in two soil la- yers (0-20 cm, 20-40 cm) under four treatments (CK, NPK, M, MNPK) from a 35-year continuous fertilization field at the Ministry of Agriculture Key Field Observation Station of Harbin Black Soil Ecology Environment using Biolog-ECO method. The results showed that: in the 0-20 cm soil layer, combined application of organic and inorganic fertilizer(MNPK) increased the rate of soil microbial carbon source utilization and community metabolism richness, diversity and dominance; In the 20-40 cm layer, these indices of the MNPK treatment was lower than that of the NPK treat- ment; while NPK treatment decreased soil microbial community metabolism evenness in both layers. Six groups of carbon sources used by soil microbes of all the treatments were different between the two soil layers, and the difference was significant among all treatments in each soil layer (P0.05) , while the variations among treatments were different in the two soil layers. Canonical correspondence analysis (CCA) showed that soil microbial community metabolic function of all the treatments was different between the two soil layers, and there was difference among all treatments in each soil layer, while the influences of soil nutrients on soil microbial community metabolic function of all treatments were similar in each soil layer. It was concluded that long-term different fertilization affected soil microbial community functional diversity in both tillage soil layer and down soil layers, and chemical fertilization alone had a larger influence on the microbial community functional diversity in the 20-40 cm layer.

Like bacteria, fungi play an important role in the composting process as major decomposers of organic substances. As only a small fraction of the fungi present in composting can be cultured because conventional microbiological techniques limited information on the composition of fungal communities in composting. Molecular methods are expected to give a more realistic view of species richness and distribution. For this purpose, we selected universal PCR primer set that allow the specific amplification of fungal 18S-ribosomal-DNA (rDNA) sequences. DNA was extracted from composting samples, and 18S rDNA genes were amplified by EF4/Fung5 (0.6kb) and EF4/NS2-GC (0.4kb). DGGE analysis of the fungal community in the composting of a microcosm experiment was carried out after amplification of total DNA with both primer pairs. Clear banding patterns were obtained with amplified production. 13 different bands excised from the DGGE gel were sequenced and compared with genbank. Sequencing showed that some could not be cultured; some were efficient cellulose-degrading strains. The results showed that diversity and composition of the fungal community in the composting can be analyzed by the combination of 18S rDNA PCR amplification and DGGE.

The effect of the microbiological inocula to efficiently decompose animal manures into mature compost was studied. In general, TOC, water contents and C/N ratio decreased during decomposition in two composts and those properties dropped faster in the microbiological inocula compost than the natural compost. The total nitrogen content and NO 3 − –N behaved in the opposite manner and those properties increased faster in the microbiological inocula compost than the natural compost. The pH and NH 4 + –N increased first, and then decreased in two composts. The microbiological inocula showed a more rapid rate of temperature elevation at the start of composting and prolonged the time of high-temperature process. The microbiological inocula were able to facilitate the microbial diversity of the compost. Based on germination assays, the microbiological inocula seems to be advantageous in reducing the maturation time of cow manure compost.

A genetic diversity analysis was conducted, of 14 wild Auricularia auricula strains and 6 cultivated strains from DaXing'anling region by SRAP and ITS markers. Using PCR-SRAP system, we selected 9 pairs of primers for the wild and cultivated strains respectively, and analyzed their genetic diversity through clustering analysis. The results were as follows: 88 fragments were amplified, and the polymorphic bands were 76. The PIC (polymorphism information content) value of these markers varied from 0.048 to 0.918, averaging 0.599. Kinship of Auricularia auricula strains was determined by analyzing their ITS sequences. The software ClustalX 1.83 and MEGA 4.1 were used to conduct the phylogeny analysis. The results were as follows: ITS 1, 5.8 S, ITS2 had as many genetic loci as 52.1%. Cluster analysis of the two kinds of markers were congruous and there were more genetic diversities in wild strains than in cultivated strains. SRAP and ITS techniques can be used to analyze the genetic diversity in the future study.

Low phytic acid (LPA) crops have recently been considered as a potential way to combat nutritional and environmental issues related to seed phytic acid phosphorus (PA-P). Although, a number of LPA mutant lines have been developed in various crops, they are often featured with lower grain yield and seed viability compared with wild type (WT) parents. We recently developed several LPA mutant lines in rice with PA-P reductions varying from 33.8% to 63.6%. In this study, the performance of grain yield and seed viability of these mutants were investigated. Four of the five mutant lines had 12.5–25.6% reductions in grain yield compared to the corresponding WT parental lines. The reduction in grain weight, varying from 5.4% to 10.7%, was found to be the main causative factor of yield reduction. Similarly, LPA mutants had inferior seed viability to their corresponding WT parent varieties; all mutant lines had a significantly lower simplified vigour index (seed germination rate × seedling dry weight) than their parents, with reductions of 7.8–26.3%, although some mutant lines had similar germination rates as their WT parents. The two mutant lines, which had similar germination rates as their WT parent, however, had significantly lower field emergence rates. More pronounced differences of simplified vigour index were observed after artificial aging treatments between four LPA lines from their WT parents, implying that LPA rice seeds were more susceptible to storage than WT. The yield and yield-related traits of F 2 plants and F 3 lines from three crosses were evaluated; the results showed that while LPA was associated with significantly lower grain yield and grain weight than WT sibs, there were also LPA plants and lines that out-performed WT controls. These results implied that the negative effect of LPA mutations on grain yield might be reduced or minimized through cross and selection breeding. The implications of these findings were discussed with regard to LPA rice breeding and potential commercial production.

Background. EA therapy is a traditional therapeutic approach for alleviation of cerebral I/R-induced brain injury. We investigated the effect of EA on MCAO rat model to examine the mechanism of apoptosis in the rat hippocampus.Methods. 200 male Sprague-Dawley rats were randomly divided into sham, I/R, EA, ERK inhibitor (PD), and ERK inhibitor+EA (PD+EA) groups. Each group was subdivided into 5 groups according to different time points. Locomotor behaviors were evaluated using neurological scales and morphological examination was performed using HE staining. Apoptosis index of neural cells in local infarcted area was measured by TUNEL and p-ERK expression was detected using immunohistochemistry technique and western blot analysis.Results. Neurological deficit scores and neural apoptosis in the EA group were lower than I/R group at the same time points, respectively. At different time points, p-ERK level was increased in the ischemic hippocampal CA1 in the EA group as compared to I/R group; the increased level was increased most at 1 day, 3 days, and 1 week (p<0.01).Conclusion. EA alleviates neurological deficit, reduces apoptosis index, and simultaneously upregulates the expression of p-ERK signal pathway in rats subjected to I/R injury.

Electroacupuncture attenuates cerebral hypoxia and neuronal apoptosis induced by cerebral ischemia/reperfusion injury. To further identify the involved mechanisms, we assumed that electroacupuncture used to treat cerebral ischemia/reperfusion injury was associated with the p38 mitogen-activated protein kinase (MAPK) signaling pathway. We established rat models of cerebral ischemia/reperfusion injury using the modified Zea-Longa's method. At 30 minutes before model establishment, p38 MAPK blocker SB20358 was injected into the left lateral ventricles. At 1.5 hours after model establishment, electroacupuncture was administered at acupoints of Chize (LU5), Hegu (LI4), Zusanli (ST36), and Sanyinjiao (SP6) for 20 minutes in the affected side. Results showed that the combination of EA and SB20358 injection significantly decreased neurologic impairment scores, but no significant differences were determined among different interventional groups. Hematoxylin-eosin staining also showed reduced brain tissue injuries. Compared with the SB20358 group, the cells were regularly arranged, the structures were complete, and the number of viable neurons was higher in the SB20358 + electroacupuncture group. Terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end labeling assay showed a decreased apoptotic index in each group, with a significant decrease in the SB20358 + electroacupuncture group. Immunohistochemistry revealed reduced phosphorylated p38 expression at 3 days in the electroacupuncture group and SB20358 + electroacupuncture group compared with the ischemia/reperfusion group. There was no significant difference in phosphorylated p38 expression between the ischemia/reperfusion group and SB20358 group. These findings confirmed that the electroacupuncture effects on mitigating cerebral ischemia/reperfusion injury are possibly associated with the p38 MAPK signaling pathway. A time period of 3 days could promote the repair of ischemic cerebral nerves.

Taking the cow dung and straw as composting raw materials, effect of cellulose-decomposing strain on microbial community of cow manure compost was investigated with the traditional culture method and PCR-DGGE technique. The results showed that the microbiological inocula showed a more rapid rate of temperature elevation at the start of composting and prolonged the time of high-temperature process and increased the number of microbial. The DGGE map of cellulose-decomposing strain compost was different from natural compost, the succession of microbial community in cellulose-decomposing strain was faster than natural compost. Sequence comparison revealed that the Pseudomonas sp. of bacterial appeared at the initial stage and Acinetobacter sp., Flavobacteria were existed at the high-temperature process in natural compost; while Arthrobacter sp. was appeared at the high-temperature process in cellulose-decomposing strain compost. Bacillus sp. was dominant species at middle and later stage in natural compost and cellulose-decomposing strain compost. Eimeriidae of fungal appeared in compost materials, Aspergillus and thermophilic fungi were dominant species at the high-temperature process in natural compost and cellulose-decomposing strain compost. Ascomycota appeared at middle and later stage in natural compost; while Basidiomycetes in cellulose-decomposing strain compost. Aspergillus was found throughout the process. This result suggested that the microbiological inocula were able to facilitate the bacterial microbial diversity of the compost; reduced the fungal microbial diversity of the compost. The aims of this study were to provide a scientific basis to the diversity of microbial community by monitoring the dynamics of microbial community in cellulose-decomposing strain compost and represent an important step towards the understanding of microbiological inocula and its function in the degradation process of compost.

Docetaxel (DOC) therapy is well tolerated and shows high response rates in patients with hormone refractory prostate cancer (HRPC). There are many reports on the effect of rapamycin (RPM) on the treatment of carcinogenesis. The goal of this study was to test whether RPM could enhance the susceptibility of both androgen-dependent and -independent prostate carcinoma cells to DOC.Prostate cancer (PC) cell lines (LNCap, PC3 and AILNCap) were cultured and treated with RPM and DOC alone or in combination. The effects of therapeutic agents on cells were determined by the WST-1 assay. Apoptosis induction was confirmed by flow cytometric analysis. The apopcyto caspase colorimetric assay kit was applied to measure the activities of caspases 3 and 9. The antitumor effects of RPM and DOC against PC cells were also assessed in nude mice using four randomized groups: control, RPM, DOC and combination drug therapy by measuring tumor size. All the animals tolerated both RPM and DOC without significant weight loss.RPM and DOC caused dosage-dependent growth suppression of PC cells. RPM could increase the susceptibility of PC cells to DOC significantly, and combined treatment with RPM and DOC caused synergistic growth suppression in all examined PC cell lines by isobolographic analysis. Both RPM and DOC significantly induced apoptosis in a dosage-dependent manner. RPM (10 nmol/L), DOC (1 nmol/L), and combined treatment induced apoptosis rate were 8%, 17% and 38%, respectively (the control was 2%). RPM could promote the apoptosis induced by DOC in PC cell lines. Both RPM and DOC significantly increased the caspase activity in a dosage-dependent manner. The relative activities of caspase 9 in control, RPM, DOC and RPM + DOC groups were 0.22 +/- 0.02, 0.36 +/- 0.06, 0.47 +/- 0.05 and 0.84 +/- 0.08, respectively. The relative activities of caspase 3 were 0.21 +/- 0.02, 0.24 +/- 0.05, 0.42 +/- 0.06 and 0.81 +/- 0.09, respectively. Either RPM or DOC alone significantly inhibited the growth of PC cells in nude mice compared to the control. The combination of RPM and DOC produced a significant reduction in tumor volume when compared to RPM or DOC alone. After 5-week treatment, the tumor sizes of LNCap in control, RPM, DOC and RPM + DOC groups were (570 +/- 56) mm(3), (412 +/- 41) mm(3), (425 +/- 46) mm(3) and (221 +/- 26) mm(3), respectively.RPM could significantly increase the susceptibility of both androgen-dependent and -independent PC cells to DOC; the synergy of RPM and DOC was demonstrated. RPM enhanced the DOC-induced upregulation of caspase activity, resulting in an increasing number of cells in sub-G1 phases. The synergy of the combined treatment might be observed in both androgen-dependent and -independent PC cell lines.

Phytic acid (PA, myo-inositol 1,2,3,4,5,6-hexakisphosphate) is important to the nutritional quality of cereal and legume seeds. PA and its salts with micronutrient cations, such as iron and zinc, cannot be digested by humans and non-ruminant animals, and hence may affect food/feed nutritional value and cause P pollution of groundwater from animal waste. We previously developed a set of low phytic acid (LPA) rice mutant lines with the aim of increasing the nutritional quality of rice. Two of these lines, Os-lpa-XS110-2 (homozygous non-lethal) Os-lpa-XS110-3 (homozygous lethal), contain two mutant alleles of a LPA gene (hereafter XS-lpa2-1 and XS-lpa2-2, respectively). In this study, we mapped the XS-lpa2-1 gene to a region on chromosome 3 between microsatellite markers RM14360 and RM1332, where the rice orthologue (OsMRP5) of the maize lpa1 gene is located. Sequence analysis of the OsMRP5 gene revealed a single base pair change (C/G-T/A transition) in the sixth exon of XS-lpa2-1 and a 5-bp deletion in the first exon of XS-lpa2-2. OsMRP5 is expressed in both vegetative tissues and developing seeds, and the two mutations do not change the level of RNA transcription. A T-DNA insertion line, 4A-02500, in which OsMRP5 was disrupted, also showed the same high inorganic phosphorus phenotype as Os-lpa-XS110-3 and appeared to be homozygous lethal. PA is significantly reduced in Os-lpa-XS110-2 (~20%) and in 4A-02500 (~90%) seeds compared with their wild type lines, and no PA was detected in Os-lpa-XS110-3 using HPLC analysis. This evidence indicates that the OsMRP5 gene plays an important role in PA metabolism in rice seeds.

Chicken embryo fibroblast (CEF) is a primary cellular material to research the infectious bursal disease virus (IBDV). Constructing the cDNA expression library of CEF is the foundation to research cell tropism and find cell receptors of IBDV from CEF. In order to achieve that purpose, a high-quality cDNA expression library of CEF was constructed by Gateway technology, which could avoid using the restriction enzyme for cloning to solve technical limitation of roution method. The mRNA was extracted from chicken embryonic fibroblast. Moreover, single-strand cDNA and double-strand cDNA were synthesized by using biotin-conjugated Oligo (dT) primer in turn. The double-strand cDNA was ligated Adapter and then purified by the cDNA Size Fractionation Columns. After BP recombination reaction, a cDNA entry library was constructed with a titer of 1 x 10(6) cfu/mL, total clones of 1.2 x 10(7) cfu and an average insertion size of about 2243 bp. After LR recombination reaction, the cDNA entry library was transformed into expression library which took on a titer of 5 x 10(5) cfu/mL, total clones of 5.5 x 10(6) cfu and an average insertion size of about 2411bp. The results indicate that the constructed cDNA expression library performs a remarkable high value in both recombination rate and library coverage. As a result, the cDNA expression library, with its good quality, may facilitate to identify the receptors associated with the resistance against IBDV in chicken embryonic fibroblast and to cast new light on the mechanism of cellular tropism. Moreover, it may also provide data of chicken embryonic fibroblast in transcription level and may be helpful to study its biological functions.

Phytic acid (PA, myo-inositol 1,2,3,4,5,6-hexakisphosphate), or its salt form, phytate, is commonly regarded as the major anti-nutritional component in cereal and legume grains. Breeding of low phytic acid (lpa) crops has recently been considered as a potential way to increase nutritional quality of crop products. In this study, eight independent lpa rice mutant lines from both indica and japonica subspecies were developed through physical and chemical mutagenesis. Among them, five are non-lethal while the other three are homozygous lethal. None of the lethal lines could produce homozygous lpa plants through seed germination and growth under field conditions, but two of them could be rescued through in vitro culture of mature embryos. The non-lethal lpa mutants had lower PA content ranging from 34 to 64% that of their corresponding parent and four of them had an unchanged total P level. All the lpa mutations were inherited in a single recessive gene model and at least four lpa mutations were identified mutually non-allelic, while the other two remain to be verified. One mutation was mapped on chromosome 2 between microsatellite locus RM3542 and RM482, falling in the same region as the previously mapped lpa1-1 locus did; another lpa mutation was mapped on chromosome 3, tightly linked to RM3199 with a genetic distance of 1.198 cM. The latter mutation was very likely to have happened to the LOC_Os03g52760, a homolog of the maize myo-inositol kinase (EC 2.7.1.64) gene. The present work greatly expands the number of loci that could influence the biosynthesis of PA in rice, making rice an excellent model system for research in this area.