棉花洞A型核雄性不育系花药败育过程中的生化变化

研究了陆地棉洞A型核雄性不育系(抗A1,MA)不育和可育花药不同发育时期可溶性碳水化合物、游离氨基酸和IAA、GA3、ABA含量的动态变化。结果表明,不育花药中可溶性糖含量偏高,缺乏淀粉积累;有4种游离氨基酸含量在可育与不育花药问存在显著差异,其中不育花药天门冬氨酸含量偏高,这可能是其败育的原因之一,而脯氨酸、精氨酸、苯丙氨酸含量异常,则是不育花药败育的结果;在花药主要败育时期之前,不育花药中ABA含量极显著偏高,IAA、GA3含量极显著偏低。不育花药中IAA、GA3、ABA含量变化与洞A型核雄性不育系花药败育密切相关。     

甘蓝胞质雄性不育系及其保持系花药和叶片生化特性分析

对甘蓝胞质雄性不育系CMS158及其保持系花药激素、游离氨基酸和叶片叶绿素含量进行了比较研究。结果表明,不育系花药KT和IAA含量极显著低于保持系,GA含量不育系和保持系没有显著差异。游离氨基酸总量不育系花药极显著高于保持系,脯氨酸和胱氨酸含量不育系花药极显著低于保持系,赖氨酸含量两系无明显差异,苏氨酸在两系中均未检出,其余氨基酸含量均是不育系花药高于保持系;不育系花药中丝氨酸含量最高,保持系花药中脯氨酸含量最高,两系中天冬氨酸和脯氨酸含量的差异最大。叶片叶绿素含量不育系和保持系无显著差异。     

Relationship Between Male Fertility and Endogenous Phytohormones in Photoperiod-Sensitive Genic Male-Sterile Rice

A spontaneous male sterile rice plant (Oryza sativa L. cv. Nongken 58S) "Photoperiod-sensitive Genic Male-sterile Rice has been found to be male sterile under long day cycles (LD) and fertile in short day cycles (SD). The period from secondary rachis-branch and spikelet primodia to pollen mother cell formation in the process of panical development was the photoperiod-sensitive stage for fertility alternation. The phenotype of this mutant was reported to be controlled by two pairs of recessive alleles. The research on relationship between the fertility alternation and phytohormone action in this mutant have been performed by Chinese scientists since 1985. In order to study the mechanism of fertility alternation in Nongken 58S, endogenous IAA, ABA, GA1 and GA4 in apical leaves and reproductive organs in different development stages under LD and SD conditions have been quantiatvely and qualitatively identified by GC-MS-SIM method. It was found that endogenous IAA in apical leaves at the stage of pistil and stamen primodia formation and in panicles at pollen mother cell stage of Nongken 58S with LD condition was deficient comparing with those in SD. Endogenous ABA level in panicles at pollen mother cell stage, in spikelets at uninucleate stage and in anthers at anthesis stage of Nongken 58S-LD were lower than those in SD. ABA levels in corresponding organs and developmental stages of wild type of rice, "Nongken 58" were always higher in LD treatment than those in SD. Endogenous IAA, GA1 and GA4 levels in anthers at anthesis stasge of "Nongken 58"-LD were increased obviously. Thus it appeared that "Nongken 58" possess stronger resistance to LD stress than Nongken 58S. It is concluded that IAA deficiency of reproductive organs at early developmental stage, ABA decrease implying poor resistance to LD stress and reduction of GAs in late developmental stages were the factors causing the anther sterility in Nongken 58S-LD.     

辣椒胞质雄性不育系和保持系内源激素含量的比较

以2个辣椒品系(199807、199803)的胞质雄性不育系和相应保持系为实验材料,采用酶联免疫吸附法(ELISA)测定IAA、(Z ZR)、GA3和ABA等内源激素含量,用气相色谱分析仪测定乙烯(ETH)释放量,对辣椒胞质雄性不育系和相应保持系内源激素含量变化规律进行研究.实验结果表明:在四分小孢子之前,花药中的IAA含量不育系显著高于保持系,在四分小孢子时期花药和花蕾中的IAA含量出现转折,到花粉粒成熟期的花蕾和花药以及开花期叶片中的IAA含量均是不育系显著低于保持系;小孢子各发育时期花药以及花期叶片中GA3含量均是不育系高于保持系,但花粉粒成熟期化蕾中GA3含量为不育系低于保持系;小孢子不同发育时期的花药以及花期叶片中ABA含量始终足不育系显著高于保持系,而花粉粒成熟期花蕾中ABA含量不育系与保持系没有显著差异;花粉粒成熟期的花蕾和花期叶片中ETH释放量表现为不育系显著高于保持系.同时,花粉粒成熟期的花蕾、花药和叶片中IAA/ABA、(Z ZR)/ABA、GA3/ABA、IAA/GA3、(Z ZR)/GA3等5个激素的比值均有不育系低于保持系的趋势.本实验结果说明辣椒的育性表现与花器和叶片等组织中内源激素的含量变化有关,花药和花期叶片中IAA亏缺、GA3和ABA增加以及化蕾和叶片中ETH过度产生,都有可能导致辣椒雄性不育.     

Control of abscisic acid catabolism and abscisic acid homeostasis is important for reproductive stage stress tolerance in cereals

Drought stress at the reproductive stage causes pollen sterility and grain loss in wheat (Triticum aestivum). Drought stress induces abscisic acid (ABA) biosynthesis genes in anthers and ABA accumulation in spikes of drought-sensitive wheat varieties. In contrast, drought-tolerant wheat accumulates lower ABA levels, which correlates with lower ABA biosynthesis and higher ABA catabolic gene expression (ABA 8'-hydroxylase). Wheat TaABA8'OH1 deletion lines accumulate higher spike ABA levels and are more drought sensitive. ABA treatment of the spike mimics the effect of drought, causing high levels of sterility. ABA treatment represses the anther cell wall invertase gene TaIVR1, and drought-tolerant lines appeared to be more sensitive to the effect of ABA. Drought-induced sterility shows similarity to cold-induced sterility in rice (Oryza sativa). In cold-stressed rice, the rate of ABA accumulation was similar in cold-sensitive and cold-tolerant lines during the first 8 h of cold treatment, but in the tolerant line, ABA catabolism reduced ABA levels between 8 and 16 h of cold treatment. The ABA biosynthesis gene encoding 9-cis-epoxycarotenoid dioxygenase in anthers is mainly expressed in parenchyma cells surrounding the vascular bundle of the anther. Transgenic rice lines expressing the wheat TaABA8'OH1 gene under the control of the OsG6B tapetum-specific promoter resulted in reduced anther ABA levels under cold conditions. The transgenic lines showed that anther sink strength (OsINV4) was maintained under cold conditions and that this correlated with improved cold stress tolerance. Our data indicate that ABA and ABA 8'-hydroxylase play an important role in controlling anther ABA homeostasis and reproductive stage abiotic stress tolerance in cereals.     

水稻细胞质雄性不育系及其保持系幼穗发育过程中内源激素的变化

利用酶联免疫测定技术研究了水稻细胞质雄性不育系珍汕97A及其保持系珍汕97B在幼穗发育过程中叶片、幼穗和花药中内源IAA、GA1＋4、ABA和iPAs含量的动态变化。结果表明,1）从幼穗发育的雌雄蕊形成期到三核花粉期,保持系叶片中IAA水平高于不育系,并在二核花粉期最高;在幼穗和花药中也以保持系为高。2）保持系与不育系叶片中GA1＋4含量变化趋势相似,均为先升后降,但从单核到三核花粉期以保持系为高;在幼穗和花药中也都以保持系为高。3）不育系叶片中ABA水平在幼穗发育早期明显高于保持系,中期与保持系相近,后期又高于保持系;在幼穗和花药中也都以不育系为高。4）保持系叶片、幼穗和花药中iPAs含量始终显著高于不育系。5）保持系叶片中IAA＋GA1＋4＋iPAs与ABA之比值也始终高于不育系。提示不育系叶片、幼穗和花药中IAA、GA1＋4、iPAs和ABA含量出现了异常,且IAA、GA1＋4和iPAs亏缺以及ABA盈积可能与水稻细胞质雄性不育发生有关。     

ABA regulates apoplastic sugar transport and is a potential signal for cold-induced pollen sterility in rice

Cold temperatures cause pollen sterility and large reductions in grain yield in temperate rice growing regions of the world. Induction of pollen sterility by cold involves a disruption of sugar transport in anthers, caused by the cold-induced repression of the apoplastic sugar transport pathway in the tapetum. Here we demonstrate that the phytohormone ABA is a potential signal for cold-induced pollen sterility (CIPS). Cold treatment of the cold-sensitive cultivar Doongara resulted in increased anther ABA levels. Exogenous ABA treatment at the young microspore stage induced pollen sterility and affected cell wall invertase and monosaccharide transporter gene expression in a way similar to cold treatment. In the cold-tolerant cultivar R31, ABA levels were significantly lower under normal circumstances and remained low after cold treatment. The differences in endogenous ABA levels in Doongara and R31 correlated with differences in expression of the ABA biosynthetic genes encoding zeaxanthin epoxidase (OSZEP1) and 9-cis-epoxycarotenoid dioxygenase (OSNCED2, OSNCED3) in anthers. The expression of three ABA-8-hydroxylase genes (ABA8OX1, 2 and 3) in R31 anthers was higher under control conditions and was regulated differently by cold compared with Doongara. Our results indicate that the cold tolerance phenotype of R31 is correlated with lower endogenous ABA levels and a different regulation of ABA metabolism.     

Pollen tube growth is affected by exogenous hormones and correlated with hormone changes in styles in <Emphasis Type="Italic">Torenia fournieri</Emphasis> L.

In the present report, we described the effects of indole-3-acetic acid (IAA), zeatin (ZT), gibberellin (GA₃), and abscisic acid (ABA) on in vitro pollen germination and pollen tube growth in Torenia fournieri L. The results showed that IAA and GA₃ stimulated in vitro pollen tube growth, ABA inhibited pollen tube growth, and ZT had no significant effect on the process. The stimulating effect of exogenous IAA was particularly distinct, and led to synchronous growth of straighter and more slender pollen tubes compared with the controls. However, no significant changes were found in the germination of the treated pollen. The auxin efflux inhibitor, 10 μM 1-N-naphthylphthalamic acid (NPA), was also found to stimulate pollen tube growth. We measured the content of hormones (free IAA, ZT, GA₃, and ABA) in the stigmas and styles before and after pollination. The hormone contents of stigmas measured 0.5 h after pollination (0.5 HAP) showed that ABA content decreased, whereas the content of IAA, ZT, or GA₃ did not change significantly. The hormone level in pollinated styles (4 HAP) when pollen tubes had grown into the middle part of style was characterized by an increase in free IAA and GA₃ and a decrease in ABA, which was in agreement with the results that IAA and GA₃ promoted but ABA inhibited pollen tube growth in vitro. Furthermore, the change of IAA level in styles was most notable, which was accordant to the fact that auxin stimulated significantly pollen tube growth in vitro. Using immunoenzyme and immunogold labeling techniques and an anti-IAA monoclonal antibody, we confirmed that free IAA was present throughout style tissues, and distributed in the nucleus and cytoplasm of style cells. All these results suggested that hormones, especially IAA, play important roles in pollen tube growth of T. fournieri. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Germination and <Emphasis Type="Italic">In Vitro</Emphasis> Growth of Petunia Male Gametophyte Are Affected by Exogenous Hormones and Involve the Changes in the Endogenous Hormone Level

The data obtained characterize the changes in the contents of endogenous phytohormones (IAA, cytokinins, GA, and ABA) in germinating pollen grains and growing pollen tubes of a self-compatible clone of petunia (sPetunia hybrida L.) within an 8-h period under in vitro conditions. The hydration and initiation of germination of pollen grains brought the ABA content down to a zero level, while the levels of GA, IAA, and cytokinins increased 1.5–2-fold. Later, in the growing pollen tubes, the GA content increased twofold, while the levels of IAA and cytokinins decreased. The exogenous ABA and GA₃ considerably promoted pollen germination and pollen tube growth; however, only the treatment with GA₃ produced the maximum length of pollen tubes. The exogenous IAA promoted and the exogenous cytokinins hindered the growth of pollen tubes. The membrane potential, as assessed with a potential-sensitive dye diS-C₃-(5), considerably increased in the pollen grains treated with ABA and benzyladenine, whereas IAA and GA₃ did not practically affect it. The authors conclude that the mature pollen grains contain the complete set of hormones essential for pollen germination and pollen tube growth. ABA, GA, and IAA together with cytokinins control the processes of pollen grain hydration, germination, and pollen tube growth, respectively.__________Translated from Fiziologiya Rastenii, Vol. 52, No. 4, 2005, pp. 584–590.Original Russian Text Copyright © 2005 by Kovaleva, Zakharova, Minkina, Timofeeva, Andreev.     

2种石蒜生长发育期鳞茎内源激素的动态变化

应用酶联免疫吸附测定法（ELISA）研究了石蒜与中国石蒜不同生长发育期鳞茎内源激素质量摩尔浓度的动态变化,分析了内源激素与2种石蒜生长发育的关系。结果表明,花芽分化前期2种石蒜鳞茎IAA浓度较低,而iPAs、ABA与GAs浓度较高;临近抽葶IAA浓度均有所增加,而iPAs与Zrs、ABA与GAs浓度均降到极值。花期ABA、GAs与ZRs浓度均有所回升,说明高浓度的ABA与GAs对2种石蒜的开花可能起正向调控的作用,但对叶生长的协同规律不明显。内源激素比例分析表明,ZRs/IAA、GAs/IAA、ABA/GAs三者比例高有利于2种石蒜的花原基分化,三者比例低则有助于2种石蒜的叶生长。     

辣椒杂种一代生化特性与农艺性状的灰色关联分析

用灰色关联分析方法研究了辣椒雄性不育杂种一代农艺性状与单株产量间、花蕾、叶片中生化物质含量与农艺性状间关系的密切程度。结果表明,农艺性状与单株产量问关联度的大小顺序依次为株幅、株高、果长、结果数、单果质量、第一花节位、果宽和侧枝数,花蕾中生化物质含量与农艺性状问总体关联度的大小顺序依次为可溶性糖、可溶性蛋白质、过氧化物酶活性、脱落酸、生长素、游离脯氨酸和玉米素,叶片中生化物质含量与农艺性状问总体关联度的大小顺序依次为可溶性糖、过氧化物酶活性、游离脯氨酸、脱落酸、生长素、玉米素和可溶性蛋白质。     

Study of lanthanum on seed germination and growth of rice

A study of lanthanum nitrate on the seed germination and the growth of rice was conducted. The results of this experiment indicate that soaking in a proper concentration of La(NO3)3 could accelerate the germination of the rice seeds, significantly increase seed vigor and chlorophyll contents, and improve root growth. Because during the soaking stage with La(NO3)3 the absorbed water and imbibition process of the rice seeds was quickened, the plasma membrane permeability of the seeds was increased, O2 and H2O were easier to get into the cell, and the respiratory rate was enhanced. During the germination stage, La(NO3)3 could enhance the activities of alpha-amylase, proteinase, lipase, and other hydrolytic enzymes and the contents of plant hormones, such as IAA, GAs, CTK, and so forth, except ABA contents, changed little.     

高温对杂交水稻籽粒灌浆和剑叶某些生理特性的影响

以杂交籼稻特优559为材料,探讨了高温胁迫对水稻灌浆期剑叶中有关生理特性和籽粒灌浆速率的影响.结果表明:高温胁迫加速了剑叶叶绿素的丧失,使SOD活性明显降低,质膜透性和MDA含量明显增加,脯氨酸、AsA、GSH、可溶性蛋白质以及可溶性糖含量明显降低,籽粒灌浆速率和籽粒重下降.高温使灌浆期水稻叶片衰老加速、光合能力下降是其导致灌浆速率、结实率、粒重和籽粒产量降低的主要生理原因.     

Revision of the relationship between anther morphology and pollen sterility by cold stress at the booting stage in rice

Background and AimsCold stress in rice (Oryza sativa) plants at the reproductive stage prevents normal anther development and causes pollen sterility. Tapetum hypertrophy in anthers has been associated with pollen sterility in response to cold at the booting stage. Here, we re-examined whether the relationships between anther abnormality and pollen sterility caused by cold stress at the booting stage in rice can be explained by a monovalent factor such as tapetum hypertrophy.MethodsAfter exposing plants to a 4-d cold treatment at the booting stage, we collected and processed anthers for transverse sectioning immediately and at the flowering stage. We anatomically evaluated the effect of cold treatment on anther internal morphologies, pollen fertilities and pollen numbers in the 13 cultivars with various cold sensitivities.Key ResultsWe observed four types of morphological anther abnormalities at each stage. Pollen sterility was positively correlated with the frequency of undeveloped locules, but not with tapetum hypertrophy as commonly believed. In cold-sensitive cultivars grown at low temperatures, pollen sterility was more frequent than anther morphological abnormalities, and some lines showed remarkably high pollen sterility without any anther morphological alterations. Most morphological anomalies occurred only in specific areas within large and small locules. Anther length tended to shorten in response to cold treatment and was positively correlated with pollen number. One cultivar showed a considerably reduced pollen number, but fertile pollen grains under cold stress. We propose three possible relationships to explain anther structure and pollen sterility and reduction due to cold stress.ConclusionsThe pollen sterility caused by cold stress at the booting stage was correlated with the frequency of entire locule-related abnormalities, which might represent a phenotypic consequence, but not a direct cause of pollen abortion. Multivalent factors might underlie the complicated relationships between anther abnormality and pollen sterility in rice.     

Genome duplication effects on pollen development and the interrelated physiological substances in tetraploid rice with polyploid meiosis stability

The breeding of polyploid rice made no breakthrough for a long time because of low seed set. The discovery and application of polyploid meiosis stability (PMeS) material played a pivotal role in solving this problem. Our results indicated that genome duplication led to different outcomes in different rice cultivars in terms of pollen fertility, viability, and the accumulation of important physiological substances such as free proline and endogenous hormones. Pollen from the PMeS HN2026-4X lines showed a high fertility and viability similar to those of HN2026-2X (4X indicates tetraploid while 2X indicates the diploid), whereas both rates decreased dramatically in Balilla-4X. The results of pollen microstructure and ultrastructure investigations suggested that the pollen development pattern in HN2026-4X appeared normal at all stages, but a lot of changes were discovered in Balilla-4X. Stable meiosis, timely tapetum degradation, and normal mitochondria development were critical factors insuring the high frequency pollen fertility of PMeS rice. The free proline content increased markedly in HN2026-4X as compared to HN2026-2X, but it was decreased for Balilla-4X. Genome duplication effects on regulating endogenous hormones accumulation in pollen were evident, resulting in the clear difference between PMeS HN2026-4X and Balilla-4X. The accumulation of IAA, ZR, and GA in mature pollen distinguished HN2026-4X from Balilla-4X, which was linked to normal pollen development. In particular, the excessive accumulation of ABA at the meiosis stage may be correlated to disorganized meiosis in Balilla-4X. All the results provided unequivocal evidence that genome duplication played specific roles in the normal pollen development of PMeS HN2026-4X.     

Relationship Between PSⅡExcitation Pressure and Content of Super High-Yielding Hybrid Rice

The changes in photochemical features of PhotosystemⅡ(PSⅡ) and contents of Rubisco large subunit (RLS) and small subunit (RSS) in flag leaf from 75DAS to 113DAS (from filling to harvesting stages) were investigated in two hybrid rices (Oryza sativa L.) cv. Liangyoupeijiu and cv. Shanyou 63 grown in the field. Liangyoupeijiu is a super high-yielding rice and Shanyou 63 has widely been planted in China in these years. The results indicate that soluble protein and chlorophyll in both cultivars degraded slowly at first and dramatically thereafter. The degradation speed of soluble protein in Shanyou 63 was faster than that in Liangyoupeijiu. Both Fv/Fm and qP decreased in parallel with leaf senescence, whereas qN fell at first and then rose. No significant change in excitation pressure (1-qP ) was found before 89DAS but a sharply increase in both cultivars after it occurred. Excitation pressure rose more rapidly in Shanyou 63 than that in Liangyoupeijiu. The changes of RLS and RSS content exhibited the same trend as that of soluble protein content. A better linear correlation between RLS, RSS degradation and elevation of (1-qP ) were shown in both cultivars. We suggest that the increase in PSⅡ excitation pressure possibly induced the quick senescence process in rice flag leaf. The high-yielding of Liangyoupeijiu may be due to its maintenance of stronger photosynthetic capacity, longer and more stable photosynthetic functional du-ration than that of Shanyou 63.     

开花期低温胁迫对水稻花粉性状及剑叶理化特性的影响

以耐冷水稻品种996和冷敏感品种4628为材料,开花期在人工气候室进行7 d低温（06:00-8:00和19:00-23:00,19 ℃;08:00-10:00和16:00-19:00,21 ℃;10:00-16:00,23 ℃;23:00-06:00,17 ℃）和适温（06:00-8:00和19:00-23:00,24 ℃;08:00-10:00和16:00-19:00,26 ℃;10:00-16:00,30 ℃;23:00-06:00,22 ℃)处理,研究了低温胁迫对水稻花药开裂、花粉性状及剑叶叶绿素、可溶性糖和可溶性蛋白质含量、膜透性等理化特性的影响.结果表明：开花期低温胁迫导致水稻花药开裂系数、花粉萌发率显著下降,中部和下部颖花的不育花粉率增加.996的花药开裂系数和花粉萌发率显著高于4628,表明耐冷品种996在开花期低温胁迫下能保持较好的花粉散落特性和花粉萌发特性.低温胁迫下,996的剑叶可溶性蛋白质和游离脯氨酸含量及其增幅显著高于4628,而丙二醛含量和相对电导率及其增幅却显著低于4628,说明耐冷品种在低温胁迫下的保护性反应更迅速和强烈,其膜结构及功能更稳定.     

The role of ABA in freezing tolerance and cold acclimation in barley

The role of ABA in freezing resistance in nonacclimated and cold‐acclimated barley ( Hordeum vulgare L.) was studied. Eleven nonacclimated cultivars differed in their LT₅₀, ranging from −10.8 to −4.8°C. Sugars, free proline, soluble proteins and ABA were analyzed in nonacclimated cultivars and during cold acclimation of one cultivar. There was an inverse correlation between LT₅₀ and both ABA and sucrose contents. Exogenous ABA caused a decrease in the freezing point of leaf tissue in the cultivar with the lowest level of endogenous ABA, but not in the cultivar with the highest level, suggesting that ABA in the latter may be near the optimum endogenous level to induce freezing tolerance. Plants of cv. Aramir treated with ABA or allowed to acclimate to cold temperature increased their soluble sugar content to a similar level. The LT₅₀ of leaves of cold‐acclimated cv. Aramir decreased from −5.8 to −11.4°C, with biphasic kinetics, accumulating proline and soluble sugars with similar kinetics. The biphasic profile observed during cold acclimation could be a direct consequence of cryoprotectant accumulation kinetics. ABA and soluble protein accumulation showed a single step profile, associated mainly with the second phase of the LT₅₀ decrease. Thus, a significant increase in endogenous ABA is part of the response of barley to low temperature and may be required as a signal for the second phase of cold acclimation. Endogenous ABA contents in the nonacclimated state may determine constitutive freezing tolerance.     

Mechanism of low‐temperature‐induced pollen failure in rice

Low‐temperature stress during microspore development alters cellular organization in rice anthers. The major cellular damage includes unusual starch accumulation in the plastids of the endothecium in postmeiotic anthers, abnormal vacuolation and hypertrophy of the tapetum, premature callose (1,3‐β‐glucan) breakdown and lack of normal pollen wall formation. These cellular lesions arise from damage to critical biochemical processes that include sugar metabolism in the anthers and its use by the microspores. Failure of utilization of the callose breakdown product and other microspore wall components like sporopollenin can also be considered as critical. In recent years, considerable progress has been made in the understanding of major biochemical processes including the expression of critical genes that are sensitive to low temperature in rice and cause male sterility. This paper combines a discussion of cellular organization and associated biochemical processes that are sensitive to low temperatures and provides an overview of the potential mechanisms of low‐temperature‐induced male sterility in rice.     

水稻花药对高温胁迫的生理响应

为了探明水稻花药在高温胁迫下的生理反应及适应机理,以耐热水稻品系996和热敏感水稻品系4628为材料,在人工气候室进行高温（9：00-17：00,37℃;17：00-9：00,30℃）和适温处理（9：00-17：00,30℃;17：00～9：00,25℃）,研究高温胁迫对水稻花药可溶性糖、可溶性蛋白质、热稳定蛋白、维生素C含量、膜透性及内源激素含量等生理特性的影响。结果表明,高温使水稻花药中可溶性糖含量、可溶性蛋白质含量和维生素C含量下降,热稳定蛋白含量上升;热敏感品系4628花药中丙二醛含量和相对电导率在高温胁迫下增幅大于耐热品系996;高温胁迫下,水稻花药中GA3和IAA含量降低,ABA含量上升,耐热品系996花药中GA3、IAA含量降低幅度小于热敏感品系4628,ABA含量增加幅度小于热敏感品系4628。